Diabetes mellitus is one of the serious conditions associated with necrotizing fasciitis, a severe bacterial skin infection that spreads quickly and is characterized by extensive necrosis of the deep and superficial fascia resulting in devascularization and necrosis of the associated tissues. In addition to debridement and aggressive surgery procedures, the effectiveness of therapy depends on choosing the appropriate antibacterial agents. Hence the key to successful management is an early and accurate diagnosis. We report a case of necrotizing fasciitis caused by Finegoldia magna in a patient with type 2 diabetes mellitus.