Orezone Bomboré Drill Program Continues with Positive Results

Orezone Bomboré Drill Program Continues with Positive Results Maga core holes yield 42m at 1.4 g/t and 22.5m at 2.1 g/t New regional exploration drill targets to the south yield immediate positive results May 31, 2012 - Orezone Gold Corporation (ORE:TSX) is pleased to announce additional positive oxide and sulphide drill results from the recently completed 215,000 m infill and expansion drill program at its 100% owned Bomboré Gold Project in Burkina Faso, West Africa. Results include 351 reverse circulation (RC) holes (21,302 m) and 126 diamond drill (DD) core holes (19,744 m) from the northern portion of the 11 km long Bomboré resource (see Table 3. below). The majority of these core results are from the northern Maga and CFU area (see Map below) which accounted for approximately 20% of the 2010 resources. All but 1,366 m of RC drilling program have now been reported and a full NI 43-101 compliant resource update is underway and expected to be released in July. These results confirm the more robust nature of the P8P9 and Maga areas with respect to continuity, widths and grades. said Ron Little, CEO for Orezone. Although the average depth of drilling has only been increased from 60 m to 120 m, significant mineralization has been intersected at depths of up to 255 m. This and the results reported to date highlights the potential to significantly expand and upgrade the Bomboré resource and improve the grade and preliminary economics of the project announced in June 2011. Metallurgical Test Program A metallurgical test program on the oxide and sulphide ores is now complete and a summary of the results is expected in June. Results to date indicate recoveries of +90% from oxides using a standard CIL process. The results will be integrated into the next round of Whittle pit resource modeling and will form the basis for developing a processing flow sheet, plant capacity, equipment selection and sizing and capital and operating cost estimates for the Definitive Feasibility Study ( DFS ). Project Management Addition The Company is also pleased to announce that Mr. Claude Poulin has been hired as the Bomboré Project Manager to assist with the completion of the DFS and to transition the project team from exploration to development. Claude has more than 30 years of experience in the mining industry and holds a BSc Eng. degree and an MBA. He has considerable gold mine development and operation experience in West Africa including the Morila and Sadiola mines in Mali for Anglogold Ashanti, the Essakane mine for IAMGOLD and the Mana mine for SEMAFO in Burkina Faso. Phase 2 Resource Expansion Drilling Further expansion and exploration drilling has continued since the completion of the 215,000 m program in March. Approximately 25,000 of core and RC drilling has been completed in the Southern region, mostly at Siga South, utilizing two core rigs and Orezone s own RC rig. A number of new regional targets based on previous auger drilling are also being tested during this Phase 2 drilling program. The Phase 1 program included some 142 scout RC holes on auger targets, of which several have returned positive results (see 1

Table 6 below). The follow-up RC drilling on the P17N, P16 and P8P9 (see Map below) scout drilling results has now been completed and results are expected in June and July. The follow up program will continue in a similar fashion in the Northern region, based on the auger and scout drilling results, only after the rainy season in Q4. None of the Phase 2 results will be incorporated into the July resource update. Regional Exploration New Discoveries In May 2012, Orezone completed a 1,185-hole (4,860 m) auger drilling program on a series of new regional targets where the assay results are expected in June. The reconnaissance mapping and prospecting program on the new Toéyoko permit to the southwest identified two promising targets on the permit. The first is P13 (see Map below), an 11 km long structure extending north onto the Bomboré permit with similar geology to that of the Siga West-Siga South deposit. This structure is associated with anomalous gold-in-soil geochemistry and with several gold workings where 11 grab and chip samples averaged 1.1 g/t (maximum of 4.0 g/t). The target has been covered by the recent auger drilling program using a 400 m by 25 m drilling pattern. The second target, P17S (see Map below), is located 1,600 m to the south of the P17 deposit that was included in the 2010 resource estimate. Grab and chip sampling of gold workings within the target area returned an average of 2.8 g/t from 13 samples of felsic intrusive material (maximum of 7.6 g/t), and an average of 1.1 g/t from 27 samples of sheared intermediate to mafic intrusive (maximum of 8.3 g/t). The Company completed three core holes on two fences 100 m apart on this target in April, all of which intersected gold mineralization in felsic intrusives hosted in sheared meta-gabbro (see Table 5. below). The uncut grade is averaging 2.9 g/t over a core length of 6.25 m (maximum of 10.2 g/t). The true width of these mineralized intervals is unknown at this stage. The P17 deposit and the new P17S prospect are both associated with a 5 km NNE-oriented metagabbroic intrusive. Three auger fences have tested the possible strike extension of the P17S prospect. A highresolution resistivity survey is planned during the rainy season over this new target area to better constrain the geological interpretation. Pending results of this survey and further auger drilling results, the new P17S prospect may receive additional expansion drilling during Q4. Table 1. Cumulative Current Program Results Reported to Date Current Program Results Average Grade Zone Holes meters Uncut (g/t) Cut 1 (g/t) KT RC 41 2,137 1.39 1.23 KT DD 4 442 1.73 1.67 CFU RC 126 7,805 1.54 1.06 CFU DD 24 3,738 1.32 0.97 Maga RC 331 20,651 1.23 1.09 Maga DD 131 20,019 1.19 1.09 P8P9 RC 617 39,651 1.20 1.02 P8P9 DD 173 28,109 1.19 1.00 North RC 1,115 70,244 1.23 1.05 North DD 332 52,307 1.20 1.03 2

Current Program Results Average Grade Uncut Cut 1 Zone Holes meters (g/t) (g/t) P11 RC 239 12,517 1.02 0.98 P11 DD 75 10,878 1.07 0.97 Siga E RC 182 9,893 1.05 0.96 Siga E DD 78 11,354 1.27 1.06 Siga W RC 146 7,401 0.93 0.89 Siga W DD 74 10,450 0.90 0.87 Siga S RC 208 10,517 2.20 0.97 Siga S DD 66 10,513 1.09 1.01 South RC 775 40,328 1.45 0.95 South DD 293 43,195 1.07 0.98 P17 N RC 4 201 0.98 0.98 P17 N DD 0 0 P17 RC 25 1,227 2.24 1.86 P17 DD 23 2,879 1.50 1.38 P16 RC 29 1,544 1.36 1.30 P16 DD 26 3,831 2.73 1.65 SE RC 58 2,972 1.66 1.49 SE DD 52 7,124 2.33 1.56 All RC 1,948 113,544 1.32 1.03 All DD 677 102,625 1.21 1.04 1 Weighted average grade of individual assays, cut to 5 g/t, that occur both in and outside the 2010 Whittle pit shells Table 2. Breakdown of Drilling Meterage for this Release Zone Diamond Drill Reverse Circulation # of holes meters # of holes meters KT 4 442 41 2,137 CFU 20 3,085 117 7,223 Maga 72 11,147 189 11,689 P8P9 14 2,328 4 253 P16 10 1,848 0 0 Siga S 6 894 0 0 P17S 3 414 0 0 TOTAL 129 20,158 351 21,302 3

Table 3. Highlights of Diamond Drill Hole Results for this Release (Includes holes previously reported for which the final total assay results are now available) From To Length Uncut Grade 2 Cut Grade 3 Total Zone Section Hole # (m) (m) (m) (g/t) (g/t) Assay 4 CFU 3150 BBD0729 28.50 36.00 7.50 13.37 4.14 Pending KT 6175 BBD0725 61.00 68.00 7.00 3.15 2.91 Maga 4425 BBD0639 108.00 149.00 41.00 1.00 1.00 Pending Maga 4400 BBD0820 137.00 189.00 52.00 1.16 1.09 Pending Maga 4350 BBD0738 77.00 95.00 18.00 1.12 1.12 Pending Maga 4325 BBD0688 93.00 112.00 19.00 1.18 1.18 Pending Maga 4075 BBD0737 172.00 199.00 27.00 1.08 0.99 Pending Maga 4025 BBD0735 24.00 42.00 18.00 1.74 1.74 Maga 3975 BBD0817 0.00 22.50 22.50 2.62 2.09 Pending Maga 3975 BBD0817 126.00 156.00 30.00 1.25 1.25 Pending Maga 3900 BBD0685 156.00 178.00 22.00 2.33 1.52 Pending Maga 3875 BBD0733 29.00 71.00 42.00 1.42 1.42 Pending Maga 3825 BBD0684 52.00 81.00 29.00 1.43 1.43 Pending Maga 3625 BBD0803 105.00 113.00 8.00 5.88 2.87 P8P9 1950 BBD0544 187.00 214.00 27.00 1.02 1.02 P8P9 1900 BBD0612 78.00 99.00 21.00 1.88 1.69 P8P9 1900 BBD0615 127.00 136.00 9.00 2.34 2.34 P8P9 1650 BBD0810 0.00 10.00 10.00 2.91 2.63 P8P9 1650 BBD0810 96.00 113.00 17.00 1.34 1.34 P8P9 1600 BBD0605 74.00 104.00 30.00 0.85 0.85 P8P9 1600 BBD0606 84.00 114.00 30.00 1.07 1.03 P8P9 1450 BBD0491 116.00 138.00 22.00 8.15 0.92 P8P9 950 BBD0387 73.00 98.00 25.00 0.81 0.81 P8P9 850 BBD0759 59.00 68.00 9.00 3.76 2.27 P8P9 750 BBD0806 158.00 180.00 22.00 1.21 0.94 P16 44325 BBD0813 198.00 216.00 18.00 1.22 1.22 Pending P16 44275 BBD0766 80.00 101.00 21.00 1.20 1.17 P16 44275 BBD0766 104.00 129.00 25.00 1.44 1.42 P16 44275 BBD0768 106.00 115.00 9.00 5.18 2.31 Pending P16 44275 BBD0768 136.00 154.00 18.00 10.55 1.57 Pending P16 44225 BBD0447 75.00 90.00 15.00 5.91 3.42 P16 44225 BBD0447 123.00 137.00 14.00 1.74 1.74 2 Weighted average grade of uncut individual assays 3 Weighted average grade of individual assays cut to 5 g/t 4 Composite width and grade are preliminary where leach residue fire assay results are pending 4

Table 4. Highlights of Reverse Circulation Results for this Release (Includes holes previously reported for which the final total assay results are now available) From To Length Uncut Grade 5 Cut Grade 6 Zone Section Hole (m) (m) (m) (g/t) (g/t) Assay 7 CFU 2850 BBC3111 3.00 17.00 14.00 1.37 1.37 Pending CFU 2550 BBC3078 44.00 52.00 8.00 2.02 2.02 CFU 2500 BBC2822 25.00 40.00 15.00 1.05 1.05 Pending Maga 4500 BBC2810 43.00 67.00 24.00 2.40 2.16 Pending Maga 4350 BBC2811 4.00 35.00 31.00 1.28 1.28 Pending Maga 4325 BBC2812 45.00 62.00 17.00 1.50 1.50 Pending Maga 4300 BBC2813 11.00 38.00 27.00 0.76 0.76 Pending Maga 3825 BBC3041 0.00 25.00 25.00 1.24 1.24 Maga 3825 BBC3042 34.00 50.00 16.00 1.64 1.64 Maga 3800 BBC3000 19.00 43.00 24.00 0.97 0.97 Maga 3675 BBC3019 0.00 11.00 11.00 2.86 1.70 Maga 3650 BBC2988 23.00 31.00 8.00 2.57 2.25 Pending Maga 3650 BBC2998 35.00 55.00 20.00 2.60 2.26 Maga 3600 BBC3004 19.00 31.00 12.00 3.67 2.54 Maga 3600 BBC3007 17.00 22.00 5.00 5.35 4.15 Maga 3575 BBC2990 27.00 39.00 12.00 1.43 1.43 Maga 3550 BBC2898 12.00 25.00 13.00 2.69 2.11 Maga 3550 BBC2899 33.00 44.00 11.00 2.19 2.16 Maga 3550 BBC3001 8.00 16.00 8.00 10.36 2.94 Maga 3550 BBC3001 19.00 35.00 16.00 1.71 1.70 Maga 3550 BBC3011 3.00 12.00 9.00 2.07 2.04 Maga 3550 BBC3011 49.00 54.00 5.00 3.33 3.26 Maga 3100 BBC2948 0.00 19.00 19.00 0.80 0.80 Total Table 5. Diamond Drill Hole Results from the new P17S prospect From To Length Uncut Grade 8 Cut Grade 9 Total Zone Section Hole # (m) (m) (m) (g/t) (g/t) Assay 10 P17 S 42725 TDD0001 47.00 52.00 5.00 3.57 3.23 Pending 54.00 57.00 3.00 2.08 2.08 Pending 42725 TDD0002 P17 S 70.00 74.00 4.00 5.25 4.52 Pending P17 S 42625 TDD0003 21.00 34.00 13.00 2.16 1.77 Pending 5 Weighted average grade of uncut individual assays 6 Weighted average grade of individual assays cut to 5 g/t 7 Composite width and grade are preliminary where leach residue fire assay results are pending 8 Weighted average grade of uncut individual assays 9 Weighted average grade of individual assays cut to 5 g/t 10 Composite width and grade are preliminary where leach residue fire assay results are pending 5

Table 6. Highlights of Phase 1Reverse Circulation Results on Auger anomalies (Includes holes previously reported) From To Length Uncut Grade 11 Cut Grade 12 Total Zone Section Hole # (m) (m) (m) (g/t) (g/t) Assay 13 KT 6500 BBC3207 44.00 50.00 6.00 1.08 1.08 Y KT 6300 BBC3210 8.00 11.00 3.00 2.45 2.45 Y KT 6300 BBC3210 27.00 30.00 3.00 1.34 1.34 Y KT 6100 BBC3214 0.00 9.00 9.00 1.26 1.26 Y Maga 4900 BBC2796 45.00 52.00 7.00 1.26 1.26 Y Maga 4700 BBC2789 29.00 33.00 4.00 1.56 1.56 Y Maga 4700 BBC2790 32.00 36.00 4.00 1.11 1.11 Y Maga 4700 BBC2794 3.00 11.00 8.00 0.83 0.83 Y Maga 4050 BBC2760 47.00 53.00 6.00 0.87 0.87 Y Maga 4050 BBC2761 2.00 7.00 5.00 1.17 1.17 Y Maga 3950 BBC2762 48.00 52.00 4.00 2.62 2.26 Y Maga 3800 BBC2753 20.00 28.00 8.00 2.15 2.06 OK P8P9 1800 BBC2670 14.00 18.00 4.00 1.11 1.11 OK P8P9 1800 BBC2670 31.00 34.00 3.00 1.00 1.00 OK P8P9 1400 BBC2596 30.00 33.00 3.00 1.02 1.02 OK P17 N 45750 BBC2423 38.00 47.00 9.00 1.04 1.04 OK P17 N 45750 BBC2424 18.00 21.00 3.00 1.44 1.44 OK P17 N 45750 BBC2424 28.00 38.00 10.00 0.79 0.79 OK P11 49450 BBC2398 1.00 6.00 5.00 1.11 1.11 OK P11 48300 BBC2426 4.00 15.00 11.00 0.96 0.96 OK P11 48300 BBC2426 40.00 47.00 7.00 2.05 1.52 OK P11 48200 BBC2402 9.00 15.00 6.00 1.20 1.20 OK P11 48200 BBC2425 13.00 16.00 3.00 1.44 1.44 OK Siga E 13100 BBC2400 47.00 50.00 3.00 3.93 2.24 OK P16 44150 BBC2405 9.00 22.00 13.00 1.48 1.48 OK P16 44150 BBC2406 3.00 11.00 8.00 2.94 2.76 OK P16 44150 BBC2406 18.00 34.00 16.00 1.37 1.37 OK P16 44150 BBC2406 47.00 50.00 3.00 1.18 1.18 OK The mineralized intervals are based on a lower cut-off grade of 0.5 g/t, a minimal width of 3 m and up to a maximum of two consecutive meters of dilution being included. The true width of the mineralization is approximately 85% of the drill length intervals in Maga, P16, P17 and P8P9 areas, and 95% of the drill length intervals in the Siga area. The halfcore samples were collected by Orezone employees using a diamond saw. The core samples from the weathered (oxide) zone were prepared by Abilab Burkina s.a.r.l. (a subsidiary of ALS-Chemex), BIGS Global Burkina s.a.r.l and SGS Burkina Faso s.a.r.l., and then split by Orezone to 1 kg using Rotary Sample Dividers (RSDs). A 1 kg aliquot was analyzed for leachable gold at BIGS Global Burkina s.a.r.l in Ouagadougou, by bottle-roll cyanidation using a LeachWell TM catalyst. The samples from the fresh or sulphide zone were prepared by BIGS Global Burkina s.a.r.l, SGS Burkina Faso s.a.r.l., ACTLABS Burkina Faso s.a.r.l. and Abilab Burkina s.a.r.l. in Ouagadougou and then split by Orezone to 1 kg using 11 Weighted average grade of uncut individual assays 12 Weighted average grade of individual assays cut to 5 g/t 13 Composite width and grade are preliminary where leach residue fire assay results are pending 6

Rotary Sample Dividers (RSDs). A 1 kg aliquot was analyzed for leachable gold at BIGS Global Burkina s.a.r.l in Ouagadougou, by bottle-roll cyanidation using a LeachWell TM catalyst. The RC drilling samples were divided by Orezone employees using Rotary Sample Dividers (RSDs). A 2 kg split was prepared by Abilab Burkina s.a.r.l. (a subsidiary of ALS-Chemex), BIGS Global Burkina s.a.r.l and SGS Burkina Faso s.a.r.l., and then split by Orezone to 1 kg using RSDs. A 1 kg aliquot was analyzed for leachable gold at BIGS Global Burkina s.a.r.l in Ouagadougou, by bottle-roll cyanidation using a LeachWell TM catalyst. The leach residues from all samples with a leach grade in excess of 0.2 g/t were prepared by BIGS Global Burkina s.a.r.l. and then split by Orezone to 50 g using Rotary Sample Dividers (RSDs). A 50 g aliquot was analyzed by fire assay at Abilab Burkina s.a.r.l. (a subsidiary of ALS-Chemex) or a 30 g aliquot at SGS Burkina Faso s.a.r.l. Orezone employs a rigorous Quality Control Program (QCP) including a minimum of 10% standards, blanks and duplicates. This program was executed under the supervision of Pascal Marquis, SVP Exploration for Orezone, who is a Qualified Person under National Instrument 43-101 and approved the technical information in this release. A complete table of results and the NI 43-101 Bomboré Resource Report that describes the Bomboré resource model can be found at www.orezone.com. About Orezone Gold Corporation Orezone is a Canadian company with a gold discovery track record of +10 M oz and recent mine development experience in Burkina Faso, West Africa. Bomboré, the Company s 100% owned flagship project, is one of the largest gold deposits in the country and is situated 85 km east of the capital city, adjacent to an international highway. Resources are constrained within optimized open pit shells that span 11 km, and include 1.6 Moz indicated (60.9 Mt @ 0.81 g/t) and 1.9 Moz inferred resources (60.6 Mt @ 0.96 g/t) with an average drill depth of only 60 meters. The Company has recently completed a 215,000 m drill program to significantly expand resources and support the completion of a DFS in 2012. Orezone s goal is to develop Bomboré into a world-class deposit by the end of 2012 and become a mid-tier producer by 2015. For further information please contact Orezone at (613) 241-3699 or Toll Free: (888) 673-0663 Ron Little, CEO, rlittle@orezone.com Pascal Marquis, SVP Exploration, pmarquis@orezone.com FORWARD-LOOKING STATEMENTS AND FORWARD-LOOKING INFORMATION: This news release contains certain forward-looking statements within the meaning of applicable Canadian securities laws. Forward-looking statements and forward-looking information are frequently characterized by words such as plan, expect, project, intend, believe, anticipate, estimate and other similar words, or statements that certain events or conditions may or will occur. Forward-looking statements in this release include statements regarding, among others, ; capital and operating cost estimates; gold production for the project; completion of a Definitive Feasibility Study in 2012; completion of a metallurgical test program in June 2012; completion of a resource update in July 2012; commencement of production at the Bomboré Project;. FORWARD-LOOKING STATEMENTS are based on certain assumptions, the opinions and estimates of management at the date the statements are made, and are subject to a variety of risks and uncertainties and other factors that could cause actual events or results to differ materially from those projected in the forward-looking statements. These factors include the inherent risks involved in the exploration and development of mineral properties, the uncertainties involved in interpreting drilling results and other geological data, fluctuating metal prices, the possibility of project cost overruns or unanticipated costs and expenses, the ability of contracted parties (including laboratories and drill companies to provide services as contracted); uncertainties relating to the availability and costs of financing needed in the future and other factors. The Company undertakes no obligation to update forward-looking statements if circumstances or management s estimates or opinions should change. The reader is cautioned not to place undue reliance on forward-looking statements. Comparisons between any resource model or estimates with the subsequent drill results are preliminary in nature and should not be relied upon as potential qualified changes to any future resource updates or estimates. 7

Readers are advised that National Instrument 43-101 of the Canadian Securities Administrators requires that each category of mineral reserves and mineral resources be reported separately. Readers should refer to the annual information form of Orezone for the year ended December 31, 2011 and other continuous disclosure documents filed by Orezone since January 1, 2012 available at www.sedar.com, for this detailed information, which is subject to the qualifications and notes set forth therein. Map New Targets and Prospects with Pending Results Positive RC scout drilling results with follow up RC drilling planned for Q4 MAGA/CFU KT P8P9 footwall contact, positive RC scout drilling results Follow up RC drilling results pending P11 hangingwall positive RC scout drilling results Follow up RC drilling planned for Q4 P8P9 P11 P13 target 11 km gold in soil anomaly Several artisanal gold workings along this trend Auger results pending (400 m x 25 m centers) P17N P13 P17N target with positive RC scout drilling and further results pending P17 P17S P16 target with positive RC scout drilling results and further results pending P17S positive core drilling results with auger results pending 1 km + Auger holes Siga W Siga S structure possible 3.6 km south extension Auger results pending (400 m x 25 m centers) 8