The authors report on 13 cases of gangrene of the perineum. Eight of the patients presented with a pre-existing infectious or tumoral anorectal lesion. In two cases, gangrene was a complication of a surgically treated prostatic pathology; two other patients had Fournier's disease. The last case was termed "spontaneous" as no causative factor was found. The unexpected recrudescence of this pathology, its severe nature, our limited knowledge of the pathogenic factors involved, and the difficulties encountered in treatment make analysis of this series of cases particularly interesting; moreover, despite the apparent etiological disparity of these observations, there were common anatomic, bacteriologic, and therapeutic elements. As concerns treatment, emphasis is placed on three points: prime role of surgery, the only means of obtaining precise information on lesions, broad indications for bypass colostomy, value of treatment with hyperbaric oxygen. The mortality rate remains high: 4 of the 13 patients died.