Toronto, Ontario, April 13, 2017 — Primero Mining Corp. (“Primero” or the “Company”) (TSX:P, NYSE:PPP) announced today that it has successfully resolved the work stoppage of unionized employees that began on February 15, 2017. Operations are expected to resume at Primero’s San Dimas mine in Mexico on Tuesday, April 18, 2017. The Company is also pleased to announce that it has a new Collective Bargaining Agreement (“CBA”) with the National Union of Mine, Metal, Steel and Allied Workers of the Mexican Republic (Sindicato Nacional de Trabajadores Mineros, Metalúrgicos, Siderúrgicos y Similares de la República Mexicana). The agreement provides a formal structure for regulating all aspects of the relationship between Company and its unionized employees. The Company considers the new CBA to be both fair and equitable to all parties, and provides Primero with a competitive cost structure aligned to the future success of San Dimas operations.