Angiomyolipoma (AML) is a mesenchymal tumor of the kidney that is composed of morphologically abnormal smooth muscle cells, blood vessels, and adipose-like foci. Renal AML is usually clinically asymptomatic and detected incidentally during imaging. Rarely, renal AML can cause life-threatening spontaneous massive retroperitoneal hemorrhage, known as Wunderlich syndrome. A 39-year-old man with tuberous sclerosis was admitted to the emergency room with left flank pain, hematuria, and nausea. On physical examination, there was a hard sensitive mass extending from the upper left half of the abdomen to the midline. Left renal AML and extensive retroperitoneal hematoma measuring about 360x220x195 mm were detected on abdominal computed tomography. The patient exhibited signs of hypovolemic shock and emergency total nephrectomy was performed. He was discharged from the intensive care unit on postoperative day 1 and from the hospital on day 5.