Background: Fornier gangrene is an extremely rare disease of the genitals. This disease is a result of the urogenital tract, anorectal area, and genital skin infections, appearing usually in immunocompromised patients with diabetes, obesity, and malignant neoplasms. The basic treatment of Fournier gangrene includes an emergency surgical intervention combined with antibiotic therapy and detoxification. Methods: A review of recent papers comprising studies and reviews published in 2005–2016 was performed. The clinical cases were studied at the Department of Purulent Surgery Central Clinical Hospital No. 1, where 7 patients were diagnosed and treated. Results: The etiology, pathogenesis, clinical and laboratory presentation, diagnosis, treatment, and prognosis of Fournier gangrene are described in this article. The authors have described several clinical cases of patients with Fournier gangrene and with necrotic cellulitis and fasciomyositis of anterior abdominal wall, which is a manifestation of Fournier gangrene. Making allowance for the unfavorable epidemiological situation of syphilis in Russia, the increase in the incidence of complicated, atypical chancre, and therefore, the need for differentiation of Fournier gangrene with such manifestations of syphilis as necrotizing, esthiomenous chancre, indurative edema, the appropriate clinical examples are well explained in this article.