PRIMERO REPORTS PRELIMINARY Q1 2016 PRODUCTION RESULTS; QUARTER FOCUSED ON CREATING A WORKPLACE FREE OF ACCIDENTS

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

Toronto, Ontario, April 18, 2016 --- Primero Mining Corp. (''Primero'' or the ''Company'') (TSX:P, NYSE:PPP) today announced its preliminary first quarter 2016 operating results. The Company's first quarter 2016 financial results will be released on May 4, 2016.

Highlights:

• Creating and Sustaining a Safety-First Culture: Primero's highest priority is the safety of its workers. After unacceptable safety results in 2015 at San Dimas' underground operations, Primero has been determined to transform the mine's safety culture. Through Q1 2016, Primero has focused on implementing stringent new safety standards and procedures, which include the implementation of standards for ground support in line with the Ontario Mining Regulations - a process that has not previously been applied at the San Dimas mine.

• First Quarter 2016 Production: First quarter 2016 production totalled 36,158 gold equivalent ounces1, at preliminary all-in sustaining costs2 of $1,556 per gold ounce3. Q1 production included 22,901 gold equivalent ounces from San Dimas and 13,257 ounces of gold from Black Fox. Quarterly production was impacted by changes to the mining sequence at San Dimas to include the implementation of Canadian safety standards for ground support, which resulted in the deferral of some high grade stopes. Black Fox production was affected by the limited availability of high-grade ore from the upper, remnant areas of the underground mine.

• 2016 Production and Cost Guidance Updated: The Q1 2016 production shortfall that was a result of implementing enhanced safety procedures at San Dimas, has resulted in Primero reducing its 2016 production guidance to between 230,000 and 250,000 gold equivalent ounces. All-in sustaining cost guidance is now expected to be between $975 and $1,025 per gold ounce.

''Primero invested a significant amount of time and resources during the first quarter to create a transformational shift in attitude towards achieving a workplace free of accidents. The safe operation of our two mines is our top priority and while we are encouraged to see a transformation, we know we must remain vigilant,'' stated Ernest Mast, President and Chief Executive Officer. ''Although production was well below our original expectations during this implementation period, we are committed to getting our operations up to full capacity as quickly as possible. We have a strong operational plan at San Dimas to deliver planned throughput rates with the more stringent ground control conditions for the remainder of 2016. During April, the mine has operated at production rates greater than the nameplate 2,500 tonnes per day. We also continue to believe in the future of the Black Fox mine, having recently reached the Deep Central zone mineralization on the 640 metre level. Primero's team has demonstrated dedication to our core values during this difficult and demanding time for the Company, and I look forward to delivering positive news flow through the remainder of 2016.''

Creating and Sustaining a Safety-First Culture

Primero is firmly committed to the safety of its employees, and has been working hard to affect a transformational shift in attitude towards a safety culture that supports the maintenance of a workplace free of accidents. This has included the implementation of a strict policy that ''no person should be advancing any face under unsupported ground''.

To this effect, San Dimas personnel have completed the immense task of retrofitting all active areas of the mine with standards for ground support in line with the Ontario Mining Regulations, a practice previously assessed as unnecessary due to the generally excellent rock conditions of the mine. This has required the restriction of access to certain portions of the mine and provisions for new access points to specific areas, significantly impacting the first quarter mine plan. Management reports that this comprehensive and intense implementation phase is now complete and the mine is capable of operating at planned capacity for the remainder of 2016.

Additionally, Primero's safety department has revised the San Dimas "Reglas Por La Vida" (Rules for Life), nine critical standards and operating procedures that apply to all San Dimas employees. The updated Code includes increased requirements for working under supported areas.

Company-wide safety communication has improved and operating risks are being identified and addressed earlier to avoid potential accidents. Primero has encouraged greater interaction with mining crews in the morning safety and coordination talks, and has observed a noted increase in potential incident reporting resulting in a more proactive safety environment. As a result of our efforts, San Dimas has gone more than 3 months with zero reportable incidents, and all employees are responding positively to the call for a change in attitude towards safety.

First Quarter 2016 Production

Primero produced 36,158 gold equivalent ounces during the first quarter of 2016, 41% below the same period in 2015, mainly as a result of the introduction of Canadian standards for ground support at the San Dimas mine. Preliminary all-in sustaining costs (''AISC'') for the quarter are expected to be $1,556 per gold ounce and total cash costs4 of $944 per gold equivalent ounce.

San Dimas produced 22,901 gold equivalent ounces during the first quarter, which includes 19,578 ounces of gold and 0.92 million ounces of silver. Q1 2016 preliminary AISC are expected to be $1,362 per gold ounce and total cash costs of $998 per gold equivalent ounce. First quarter production at San Dimas was impacted by changes to the mining sequence which now includes the implementation of Canadian standards for ground support, and the condition that all employees will never work under unsupported ground. As a result, mill throughput was restricted to an average of 1,639 tonnes per day (''TPD'') during the quarter.

In April, the Company was successful in re-establishing operations above the current 2,500 TPD nameplate capacity. The addition of ground support has resulted in a modified mine plan for the remainder of 2016, with the Company targeting higher grade stopes at slightly lower tonnes. The Company will continue to analyze the impact of the removal of low grade cut-and-fill stopes on its original plan of mining consistently at 3,000 TPD by the end of 2016.

Black Fox produced 13,257 gold ounces during the first quarter at preliminary AISC of $1,404 per ounce and total cash costs of $851 per ounce. Production was lower than expected as a result of limited availability of high-grade ore from the upper, remnant areas of the underground mine. Daily production rates are expected to increase through the remainder of 2016 as the underground contribution from the Deep Central zone ramps-up.

Drifting on the 640 metre level intersected initial ore in Deep Central zone in April, one month ahead of schedule. The Company is now working to complete two crosscuts through the zone and has started development of the 660 metre level ahead of initial stoping activities. Production from the Deep Central zone is expected to increase to approximately 850 TPD in Q4 2016.

2016 Production Guidance Update

As described above, the implementation of Canadian standards for ground support at the San Dimas mine has impacted production rates. This has led Primero to reduce 2016 annual production guidance by 30,000 gold equivalent ounces to between 230,000 and 250,000 gold equivalent ounces. AISC guidance is now expected to be between $975 and $1,025 per gold ounce and total cash costs are expected to be in the range of $650 to

$700 per gold equivalent ounce. Revised cash cost guidance at Black Fox reflects the inclusion of non-cash inventory draw down which was not included in the original guidance. Capital expenditures at San Dimas were also reduced by $5 million, mainly associated with the mill expansion project.

Original Guidance Revised Guidance Actual

San Dimas Black Fox Consolidated San Dimas Black Fox Consolidated

2015

Gold Production

(ounces)

Silver Production

(million ounces)

Total cash costs

145,000-

70,000-

215,000-

120,000-

70,000-

190,000-

221,060

(per gold equivalent ounce) $525-$575 $680-$730 $570-$620 $600-$650

Capital Expenditures

($ millions)$56.4 $23.6 $82.3 $51.4 $23.6 $77.3 $93.3