Drill hole DC12B575 cut 4.0 m true width of Veta del Contacto averaging 709 g/t silver and 2.12% lead.

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1 FOR IMMEDIATE RELEASE TSX EXCHANGE: SMT LIMA STOCK EXCHANGE: SMT No SIERRA METALS DRILLING DEMONSTRATES DOWNDIP POTENTIAL OF THE SILVER-RICH VETA DEL CONTACTO AT THE PROMONTORIO MINE OF ITS CUSI PROPERTY, CHIHUAHUA, MEXICO Toronto, Ontario July 9, 2013 Sierra Metals Inc. (TSX:SMT)(BVL:SMT) ( Sierra Metals or the Company ) is pleased to report that the Company drilling has extended the Veta del Contacto to a depth extent of over 700 m. In addition, detailed geologic mapping has identified two areas of wide silicification and veining at vein intersections, which are highpriority drill targets. Press Release Highlights: Drill hole DC12B575 cut 4.0 m true width of Veta del Contacto averaging 709 g/t silver and 2.12% lead. Drill hole DC12B578 cut 1.0 m true width of Veta del Contacto averaging 459 g/t silver, 4.04 g/t gold and 1.81 % lead. Geologic mapping in the San Juan area reveals a broad zone of silicification and veining at the intersection of the San Juan and Las Margaritas veins. Another zone of silicification occurs at the intersection of the La Gloria and Minerva veins. Drilling and geologic mapping continue to demonstrate the upside potential of the Cusi property, stated Daniel Tellechea, President & CEO of Sierra Metals. The results from Veta del Contacto are especially relevant because our underground workings in the Promontorio mine are only meters away from reaching this vein and the new drill results extend the silver mineralization from the surface to 700 meters depth and the vein is open at depth. Our geologists structural interpretation of this vein indicates significant potential mining width. While aggressively pursuing its target of reaching 500 tonnes per day production from the Cusi property (see press release of May 28, 2013) the Company s geologic mapping has successfully identified areas with extensive potential for additional mineralization. DRILLING EXPANDS VETA DEL CONTACTO Drilling northeast of the Promontorio shaft (insert link to Figure 1 here) with the objective of expanding the size of Veta del Contacto has demonstrated that the vein extends from the surface to at least 700 m down dip, has a strike length of about 250 m, and averages 1.95 m in width. The vein is open in both directions and to depth. Portions of the vein are wider where the vein flattens, perhaps controlled by a listric fault, where dilational zones occur. This relationship is shown in the 3D perspective view of Veta del Contacto (insert link to Figure 2 here).

2 Table 1: Selected Drill Samples from Cusi project, Chihuahua Drill Hole Core Est. True Interval (m) Width (m) Ag g/t Au g/t Pb % Mn % Vein Name DC12B V. del Contacto DC12B V. del Contacto and Unknown DC12B V. del Contacto Drill hole 624 is in progress with the objective of confirming the flattening of Veta del Contacto. It is possible that the wide intercept in hole 509 (753 g/t silver over 49 m core length (±6 m true width); see press release of December 13, 2012), in Santa Rosa de Lima about 200 meters to the SE of Veta del Contacto, is in a similar dilational zone. At this time, the Company does not have sufficient drill data to determine if these two mineralized areas are connected. Results of Geologic Mapping The Company has been conducting geologic mapping in higher-priority areas of the Cusi property. Recent results have identified two areas with the potential to host significant mineralization. San Juan Las Margaritas Veins: This area lies southwest of the San Juan Mine (insert link to Figure 3 here) that the Company is planning to begin mining late this year. These two veins merge SW of the San Juan mine and form an area of about 200 x 50 m with extensive quartz veining and silicification. This broad zone of intersection will be sampled in detail prior to drilling. Vein intersections of this type can host large volumes of mineralized rock. La Gloria Minerva Veins: The La Gloria Vein is a NNE-trending vein in the central part of the Company s active mining and exploration activities, and trends into the San Nicolas and Minerva Veins. The La Gloria vein s zone of silicification expands strongly near its intersection with the Minerva vein and forms an area m wide and about 100 m long characterized by multiple quartz veinlets and stringers. This blowout of the La Gloria vein is an excellent exploration target and will be tested by drilling. In addition, the new access ramp into the Minerva vein will be extended to this area as an underground pilot mining exercise. Cusi Property The Cusi property has an historical production of million ounces of silver between 1680 and Production was interrupted multiple times by Indian raids, wars, revolution, depression, etc. Historical operators needed grades of 1,000 g/t silver or more to be economic and many areas were left un-mined. There are multiple high-grade silver veins open to depth. Recent drilling in extension of stockwork zone cut high-grade silver over wide widths; e.g., g/t Ag (true width ± 6 m). In 2012, pilot mining production at Cusi consisted of 185 g/t silver and 0.57% lead (avg. 170 tpd). Commercial production was announced on January 1, Mining is done by cut-and-fill method. The Company plans to release a NI complaint resources report in Q The Company s objective for the Cusi property in 2013 is to advance underground development from five mines, the Santa Eduwiges, Promontorio, La India, Minerva and San Juan Mines to allow mining and development both laterally and at depth. This will bring to five the total of producing mines at the Cusi project. Management believes that Cusi is only starting to reveal its full silver potential.

3 Method of Analysis Samples were prepared at the ALS Chemex lab facility in Chihuahua, Mexico, and analyzed by ICP and AA methods at their facilities in Vancouver, Canada. Diamond drill samples sent for analysis consisted of NQ-size and BQ-size diamond core split on site, prepared by the ALS Chemex sample preparation laboratory in Chihuahua, Mexico, and assayed for Au by 50 g fire assay with AA finish. Assays for Ag, Pb, Zn, Cu and trace elements are analyzed by Induction Coupled Plasma (ICP-41) on 50g split sample at the ALS Chemex North Vancouver Laboratory. Over-limits of Ag and base metals are assayed by OG-46 method. Higher results of Au & Ag are assayed by GRA-21 method. Quality Control The technical content of this news release has been approved by Thomas L. Robyn, Ph.D., CPG, RPG, a Qualified Person as defined in NI About Sierra Metals Sierra Metals Inc. is a Canadian mining company focused on precious and base metals from its Yauricocha mine in Peru, its Bolivar mine and Cusi in Mexico. In addition, Sierra Metals is exploring several precious and base metal targets in Peru and Mexico. Projects in Peru include Adrico (gold), Victoria (copper-silver) and Ipillo (polymetallic) at the Yauricocha Property in the province of Yauyos and the San Miguelito gold properties in Northern Peru. Projects in Mexico include Bacerac (silver) in the state of Sonora, La Verde (gold) at the Batopilas Property in the state of Chihuahua, and Las Coloradas (silver) at the Melchor Ocampo Property in the state of Zacatecas. The Company s shares trade on the Bolsa de Valores de Lima and TSX under the symbol SMT. For further information on Sierra Metals, please visit or contact: Daniel Tellechea President & CEO Sierra Metals Inc. 1 (866) Matt Morrish Director, Investor Relations Sierra Metals Inc. 1 (866) This press release does not constitute an offer to sell or solicitation of an offer to buy the securities in the United States or any other jurisdiction. The Common Shares will not be and have not been registered under the United States Securities Act of 1933, as amended, and may not be offered or sold in the United States absent registration or an applicable exemption from the registration requirements. Neither the TSX nor its Regulation Services Provider (as that term is defined in policies of the TSX) accepts responsibility for the adequacy or accuracy of this release. Forward-Looking Statements Except for statements of historical fact contained herein, the information in this press release may constitute forward-looking information within the meaning of Canadian securities law. Other than statements of historical fact, all statements are forward-looking statements, which involve various known and unknown risk and uncertainties and other factors, including market conditions that may affect the Company s ability to execute its current business plan. Actual results might differ materially from results suggested in any forward-looking statements. The Company assumes no obligation to update the forward-looking statements, or to update the reasons why actual results could differ from those reflected in the forward-looking statements unless and until required by securities laws applicable to the Company. Additional information identifying risks and uncertainties is contained in filings by the Company with the Canadian securities regulators, which filings are available at

4 Figure 1: Drill Hole Location Map for Veta del Contacto

5 Figure 2: 3D Perspective View of Veta del Contacto

6 Figure 3: Vein Location Map of Cusi Mining Area