Fournier’s gangrene is a rare infectious disease characterized by rapidly necrotising fasciitis of the genital, perineal and perianal regions caused by mixed aerobic and anaerobic bacterial flora. The development and progression of the gangrene is often fulminating and can evoke multiple organ failure and death. The authors report a case of 55 year-old diabetic man with Fournier’s gangrene in course of perianal abscess. The standard clinical treatment involved extensive surgical debridement of the necrotic tissues, systemic chemotherapy with broad spectrum antibiotics and additional hyperbaric oxygen therapy. In authors’ opinion early diagnosis of the disease and intensive pharmacological and surgical treatments may improve the outcome of the patients with Fournier’s gangrene and decrease the mortality rate.