Sierra Metals Inc has filed a technical report prepared in accordance with NI 43-101 on the Bolivar mine. The report supports the disclosure made by the company in its news release dated July 9, 2018 entitled “Sierra Metals Announces Positive Preliminary Economic Assessment Results for a 67% Output Expansion at its Bolivar Mine in Mexico to 5,000 t/d Yielding a Return on Investment of 550%.”

The report is based on technical inputs from various independent consulting groups, including; SRK, Redco, Transmin Metallurgical Consultants and Anddes and was compiled under NI 43-101 standards by Mining Plus Peru SAC.

This subsequent report is based on the results from a 43-101 Technical Report on the Bolivar mine dated June 28, 2018 with an effective date of October 31, 2017 entitled “NI 43-101 Technical Report on Resources and Reserves Bolivar Mine Mexico”, that was prepared by independent SRK Consulting (US).

The Report included PEA results with:

• After-tax NPV: $214 million at an 8% discount rate
• Return on Investment: 550%
• After-tax payback period: 3.4 years
• Life of mine capital cost: $96 million
• Net after-tax cash flow: $303 million
• Total operating unit cost: $21.18/t
• Plant processing rate: 5,000 t/d
• Average copper recovery rate 85%
• Mine life: 11 years based on existing Mineral Resource Estimate
• Life of mine copper payable production: 252,507,942 lb.