&NA;Seven patients with necrotizing soft tissue infections of the perineum are described. Predisposing factors related to infection were present in four patients (diabetes mellitus, multiple myeloma, HIV, and a poorly defined immunodeficiency syndrome). Anaerobic and facultative anaerobic bacteria were cultured in each case. Two patients required skin graft closure of the debrided wounds, with the remaining wounds closed by contracture and epithelialization. A diverting sigmoid colostomy to facilitate wound care was performed on one patient who had complete dissolution of all anal sphincters. The role of hyperbaric oxygen therapy in four patients was of uncertain value.