A 44-year-old male with a history of diabetes mellitus and alcoholism for 20 years, was admitted to our hospital complaining of urinary retention and high fever. The scrotum was swollen and became necrotic partially. The inflammation and emphysema was around the anus, bilateral inguinal region, and right flank. The laboratory data showed disseminated intravascular coagulation (DIC). According to the clinical and radiological findings, we diagnosed the illness as Fournier's gangrene. Cystostomy and surgical debridment were performed in conjunction with the use of broad-spectrum antibiotics and anti-DIC therapy. After the general condition improved, the broad defect of perineal skin was covered with a free skin graft by using the negative-pressure bolster method. The graft was successful.