Importance. Fourniers gangrene occurs as a result of infectious processes of the urogenital tract, in immunocompromised patients with diabetes, obesity, malignant neoplasms. Fournier,s gangrene progresses for two to three weeks, causing tissue destruction. The basis of the treatment of Fourniers gangrene is an emergency surgical intervention in combination with antibacterial and detoxification therapy. The article reflects the importance of differential diagnosis of Fournier,s gangrene with a complicated form of primary syphiloma (phagadenic chancre). Purpose. To demonstrate the diversity of clinical manifestations of Fourniers gangrene, treatment, differential diagnosis. Materials and methods. The literature review of materials of domestic and foreign researchers, in which the etiology, pathogenesis, clinical and laboratory picture, diagnosis, treatment, and prognosis of Fourniers gangrene using the search engines Pubmed, Medline, Cochrane, Elibrary. The authors present the clinical cases of patients with Fournier,s gangrene, clinical features of complicated chancre in a patient with primary syphilis, which are necessary for adequate differential diagnosis. Results. Since 2007 to 2016 were seven men with Fournier,s gangrene on treatment in purulent surgery Department. Patients performed the autopsy, drainage of foci of necrosis, necrectomy systemic antibiotic therapy, followed by autodermoplasty. Conclusions. Fournier,s gangrene rare and severe form of lesions of the external genitalia. The prognosis of the disease is serious and depends on timely and correct treatment. The rise of complicated cases of hard chancre. It is necessary to differentiate Fournier s gangrene with clinical manifestations of syphilis.