Pheochromocytoma is challenging to diagnose, and a life-threatening situation may occur if pheochromocytoma is incorrectly diagnosed and treated. We report the first case of a lethal posttraumatic rupture of an undiagnosed pheochromocytoma in a 46-year-old man who presented with peripheral vasoconstriction and signs of peritoneal irritation after being kicked by a horse. Computed tomography, arteriography, and two exploratory laparotomies were performed. The patient died of multiorgan failure 8 h after the trauma. The diagnosis of ruptured pheochromocytoma of the left adrenal gland was made during the postmortem examination. Pheochromocytoma should be considered in cases of blunt abdominal trauma associated with unstable blood pressure, peripheral vasoconstriction and adrenal hematoma.