PRIMERO REPORTS FIRST QUARTER 2016 FINANCIAL RESULTS SAN DIMAS PRODUCTION RATES RETURNED TO PLAN IN APRIL‌‌‌‌‌‌‌‌

(Please note that all dollar amounts in this news release are expressed in U.S. dollars unless otherwise indicated.)

Toronto, Ontario, May 4, 2016 --- Primero Mining Corp. ("Primero" or the "Company") (TSX:P) (NYSE:PPP) today reported financial results for the first quarter ended March 31, 2016.‌

Highlights:

• Creating and Sustaining a Safety-First Culture: As reported on April 18, 2016, Primero's principal focus during the first quarter of 2016 was to create and sustain a safety-first culture at its operations. As a result of the significant efforts made by employees and management at all levels, Primero is pleased to report that the San Dimas mine achieved no reportable safety incidents during the first quarter while also returning the mine to production levels of 2,500 TPD.‌

• Earnings Impacted by Temporary Production Delay: First quarter earnings were directly impacted by changes to the mining sequence at San Dimas to include the implementation of enhanced ground support standards. The Company realized a net loss of $13.2 million ($0.08 per share) and adjusted net loss1 of $7.8 million ($0.05 per share) in Q1 2016. The Company generated negative operating cash flow before working capital changes during the first quarter of $8.5 million ($0.05 per share), which included $15.8 million in cash tax payments.

• Convertible Debentures Repaid in Cash: Primero repaid in full the $48 million due on its 6.5% convertible debentures on their maturity date of March 31, 2016. As at March 31, 2016 the Company had total liquidity position of $47.1 million, including $22.1 million in cash.

• Mexican Tax Update: The Company has filed procedural and substantive responses to the legal claim against its Advance Pricing Agreement ("APA") with the Mexican tax authorities ("SAT"), received in February 2016. The legal claim initiated does not identify any different basis for paying taxes, nor have any tax reassessments been received from the SAT. The Company continues to pay taxes in a manner consistent with the APA on the basis that the applicable facts and laws have not changed.

• Mine Production On-Track to Achieve Revised Guidance: The Company is pleased to report that in April both the San Dimas and Black Fox mines achieved their targeted production rates in line with the updated 2016 production guidance of between 230,000 and 250,000 gold equivalent ounces2 at all-in sustaining costs3 of between $975 and $1,025 per gold ounce.

• Mineral Resources Increased Beyond Depletion: Primero announced on March 16, 2016 that it had successfully increased total Mineral Resources across its assets in 2015, with total Measured and Indicated Mineral Resources as of December 31, 2015 of 3.1 million ounces of gold plus 88.3 million ounces of silver in addition to total Inferred Mineral Resources of 1.2 million ounces of gold and 77.1 million ounces of silver.

• Froome Zone Demonstrates Consistency of Mineralization: Recent drilling continues to delineate the highly prospective Froome Zone, located approximately 800 metres west of the Black Fox mine. Mineralization continues to demonstrate consistency over long intervals with significant gold mineralization, and Primero expects to be in a position to make a production decision on the Froome Zone in Q2 2016 Highlights from recent drilling include 6.1 g/t gold over 43.7 metres true width (16PR-G103), 6.2 g/t gold over 37.9 metres true width (16PR-G109), 5.0 g/t gold over 43.7 metres true width (16PR-G102).

''During our first quarter, we successfully implemented improved ground control procedures across our vast San Dimas mine,'' stated Ernest Mast, President and Chief Executive Officer. ''I feel a renewed sense of optimism as we enter the second quarter. On all-levels, we are pulling together as a stronger Primero team to achieve our corporate objectives, and through April we have made significant advances towards attaining these goals. The San Dimas mine successfully achieved average production rates in-line with the mill's 2,500 tonnes per day nameplate capacity. Black Fox made significant advances in developing the Deep Central zone ahead of schedule, began mining the recently identified 520 metre level in the Central Zone and completed infill drilling at the Froome deposit. I have utmost confidence in the Primero team to achieve its objectives, and I see us at an inflection point for the Company - now aligned for improved production and strong returns through the remainder of 2016 and beyond.''

Creating and Sustaining a Safety-First Culture

Primero's principal focus during the first quarter of 2016 was to create and sustain a safety-first culture at its operations. As a result of the significant efforts made by employees and management at all levels, Primero is pleased to report that the San Dimas mine achieved no reportable safety incidents during the first quarter.

As a testament to Primero's continued commitment to sustainable economic, social and environmental operations in all areas of corporate life, including business ethics, employee health and safety, involvement with the community, and preservation of the environment, in March 2016, for the fifth consecutive year, Primero was awarded the ''Empresa Socialmente Responsable'' or ''Socially Responsible Company'' designation. This prestigious award, from El Centro Mexicano para la Filantropía (''CEMEFI''), the Mexican

Centre for Philanthropy, is the result of a thorough independent assessment of Primero's corporate and social responsibility framework.

Production and Earnings Impacted by Temporary Production Delay

As reported on April 18, 2016, Primero's production in Q1 2016 was impacted by the deliberate focus on increased worker safety and the introduction of enhanced ground support standards at the San Dimas mine, leading to combined production of 36,158 gold equivalent ounces during the first quarter of 2016, 41% lower than in Q1 2015. All-in sustaining costs (''AISC'') averaged $1,555 per gold ounce during the quarter and total cash costs4 averaged $944 per gold equivalent ounce.

Given the reduced production levels, Primero generated $50.5 million of revenue in Q1 2016, 31% lower than in Q1 2015 as a result selling 29% less gold equivalent ounces at a 3% lower average realized gold price. In Q1 2016, the Company sold 38,781 ounces of gold at an average realized price of $1,156 per ounce and 1.35 million ounces of silver at an average realized price of $4.24 per ounce. Revenue in Q1 2015 totaled $73.3 million from selling 55,037 ounces of gold at an average realized price of $1,186 per ounce, and 1.90 million ounces of silver at an average realized price of $4.20 per ounce.

Silver produced at San Dimas is subject to a silver purchase agreement5 and as a result 1.35 million ounces of silver were sold to Silver Wheaton (Caymans) Ltd. ("Silver Wheaton") at a fixed price of $4.24 per ounce during the quarter. As of March 31, 2016 the Company has delivered 4.2 million ounces of silver under the San Dimas silver purchase agreement's 6.0 million ounce annual contract year threshold (which runs from August 6th to the following August 5th), after which the Company will begin selling 50% of the silver produced at San Dimas at spot market prices until August 5, 2016 when the annual threshold is reset. Silver ounces sold in Q1 2016 were higher than silver produced due to timing of shipments. Gold produced at Black Fox is subject to a gold purchase agreement6 and as a result 1,336 ounces were sold to Sandstorm Gold Ltd. ("Sandstorm") at a fixed price of $521 per ounce in Q1 2016.

The Company incurred a net loss of $13.2 million ($0.08 per share) in Q1 2016 compared with net income of

$3.6 million ($0.02 per share) for the first quarter of 2015. Adjusted loss for Q1 2016 was $7.8 million ($0.05 per share) compared with adjusted income of $1.1 million ($0.01 per share) in Q1 2015. Adjusted loss in 2016 primarily excludes the impact of foreign exchange rate changes on deferred tax balances and an adjustment to remove the normalization of inventory costs at San Dimas, net of taxes.

Primero generated negative operating cash flow before working capital changes during in Q1 2016 of $8.5 million ($0.05 per share), compared to positive operating cash flow of $18.8 million ($0.12 per share) in Q1 2015. Q1 2016 operating cash flow was affected by $15.8 million in cash payments for income taxes in Mexico, the annual payment of mining royalty taxes, a final payment for filing its 2015 tax return, and 2016 initial tax instalments.

Liquidity Expected to Improve By End of 2016

The Company's total liquidity position at March 31, 2016 totalled $47.1 million, comprised of $22.1 million in cash and $25.0 million available under its line of credit. During the quarter, a number of events significantly affected total liquidity which included the drawdown of $50.0 million from the line of credit to repay the 6.5% convertible debentures that matured on March 31, 2016 and $15.8 million in cash payments for income taxes in Mexico, the annual payment of mining royalty taxes, a final payment for filing its 2015 tax return, and 2016 initial tax instalments.

Primero expects to improve its liquidity through positive cash flows from operations and will explore other financing opportunities along with initiating the renewal of its revolving credit facility, which matures in May 2017.

Mexican Tax Update

The Company has filed procedural and substantive responses to the legal claim against its Advance Pricing Agreement ("APA") with the Mexican tax authorities ("SAT"). The procedural response is a challenge against the admission of the SAT's claim. The substantive response contains the Company's response to the SAT's claim. The APA was obtained to confirm that the Company should calculate taxes on silver produced at the San Dimas mine based on the price realized by the Company. The legal claim initiated does not identify any different basis for paying taxes, nor have any tax reassessments been received from the SAT. The Company continues to pay taxes in a manner consistent with the APA on the basis that the applicable facts and laws have not changed.

The Company believes that it is entitled to rely on the APA which is legally binding in respect of the Company's 2010 through 2014 taxation years. The Company obtained the ruling transparently and in good faith. Primero believes the APA should not be the subject of challenge by a government administration installed upon the change of government after the APA was duly issued. Primero has and will continue to invest millions of dollars in the local Mexican economy and intends to continue legal action aimed at ensuring that the Mexican tax authority respects the rule of law.

In connection with the Company's procedural challenge to the SAT's legal claim, the Mexican Federal Court recently issued an order mandating that no decision may be issued in connection with the substantive claim until the procedural challenge against the admission of SAT's claim is decided on. This procedural order is being appealed by the SAT, and the Company does not expect the order to delay the resolution of the substance of the case.

The Company has also taken other measures to defend its interests, including submitting a complaint to Procuraduría de la Defensa del Contribuyente (PRODECON or the Mexican tax Ombudsman) regarding violations of Primero's rights by the SAT.

Primero also recently obtained a ruling nullifying the Mexican customs authority's acts that suspended the Company from the import and export registries in 2015. While this order is subject to appeal, Primero believes this order recognizes Primero's compliance with Mexican laws in these matters.

The Company will continue to vigorously defend the validity of the APA and the correctness of its tax filing position.

Production On-Track to Achieve Revised Guidance

The Company is pleased to report that in April both the San Dimas and Black Fox mines achieved their targeted production rates in-line with the revised 2016 production guidance of between 230,000 and 250,000 gold equivalent ounces at all-in sustaining costs between $975 and $1,025 per gold ounce.