We present here the first case of successful management via preoperative ultrasonographic (US) study to detect a distant spreading of Fournier's gangrene (FG), which was happened in a 75-year-old man. US study showed the necrotizing infection in the periumbilical region distant 22 cm from the genital tract. A target incision of this periumbilical area and debridement of necrotic tissues was made. Computed tomography (CT) is superior to ultrasonography to confirm the diagnosis of FG and support in surgical management, but a CT evaluation in patients with FG may be limited by the frequent presence of concurrent acute renal failure or patient hemodynamic instability. Ultrasonography is an ideal technique for evaluating patients in bedside settings and can be routinely used in an emergency.