Managing the acute abdomen is a big challenge to clinicians in the emergency department. The spontaneous rupture of a renal angiomyolipoma requiring an emergency operation is occasionally encountered. We present a case of acute onset of extreme abdominal pain with a rapid decrease in her hemoglobin. Emergency exploratory celiotomy was performed under the impression of a perforated peptic ulcer with peritonitis. At surgery a retroperitoneal hemorrhage was found. The bleeding source was a ruptured mass, located at the upper pole of the left kidney. A life-saving total nephrectomy was carried out and pathology confirmed the tumor to be an angiomyolipoma. The clinical manifestations, diagnosis, and treatment of renal angiomyolipoma are briefly discussed.