Fournier's gangrene is described as a fulminant necrotizing fasciitis of the scrotum and penis. Few cases have been reported in the context of acute leukemia. We describe a case, complicating the induction treatment of an acute promyelocytic leukemia with all-trans-retinoic acid and chemotherapy. The evolution was favorable, following surgical excision and broad-spectrum antibiotic therapy. The respective roles of all-trans-retinoic acid and granulocytopenia are discussed. This devastating and life-threatening infection must be kept in mind for early clinical, bacteriological, and radiological diagnosis and surgical management.