Fournier's gangrene is a rapidly progressive, necrotizing fasciitis of the perineal, genital or perianal regions. Despite increasing knowledge about aetiology, diagnostic procedures and treatment, the gangrene is still a destructive and potentially lethal disease. In two patients, men aged 54 and 63 years, Fournier's gangrene was diagnosed. The first one died of septic shock 12 hours after admission. Surgical débridement had been performed immediately. He had a latent promyelocytic leukaemia. The second patient recovered fully after extensive surgical and antimicrobial therapy. Fournier's gangrene appears to be caused by the synergistic pathogenic action of various individually non-pathogenic commensal bacteria. Virtually all patients have an underlying systemic disorder, mainly chronic alcoholism or diabetes mellitus. Immunosupression is a predisposing factor. The gangrene requires an aggressive approach, treatment being based on the combination of haemodynamic stabilisation, antibiotic triple therapy and radical surgical débridement.