A case of malignant fibrous histiocytoma resembling mycetoma is reported. We describe a patient with a draining purulent mass and localized swelling of the left ankle. The lesion's ulcerated surface produced purulent material that contained black “granules” resembling those seen in mycetoma. Cultures revealed a heavy growth of Staphylococcus aureus and no growth of fungi. Treatment with oral antibiotics resulted in resolution of the infection with persistence of the mass. Histopathologic examination of the mass was consistent with malignant fibrous histiocytoma. This case represents an example of a malignant lesion whose initial presentation was complicated by a bacterial infection resembling a mycetoma. © 1993, American Academy of Dermatology, Inc.. All rights reserved.