A 53-year-old male was admitted with a two-day history of abdominal pain, anal bleeding, fever, diarrhea, vomiting, and mental confusion. A diagnosis of thrombosis of very large hemorrhoids (Grade 4) was made. On the day of admission, he underwent an exploring laparotomy followed by abdominoperineal resection. The peritoneal cavity was filled with pus and blood clots. Because rectal necrosis was involved, sigmoid colostomy was imperative. Twenty-eight hours after surgery, the patient demonstrated signs of soft-tissue perineal necrosis associated with progressive pain and fever. He developed a rapidly progressive gangrene of the lower limbs and scrotum followed by acute renal and respiratory failure, and he died of sepsis. At autopsy, the cadaver showed jaundice and a large gangrene of the perineum and lower limbs. The internal organs showed features secondary to sepsis complications. To the best of our knowledge, this is the first autopsy study of a patient who died because of complications of hemorrhoids.