An 18-year-old man developed a sudden onset of upper abdominal pain with vomiting. Ultrasound and computed tomographic (CT) scans revealed the spontaneous rupture of an intrahepatic artery aneurysm with subcapsular hematoma. A celiac arteriogram demonstrated a ruptured intrahepatic artery aneurysm in the right lobe of the liver, right extrahepatic artery aneurysm, obliteration of gastroduodenal artery, and abnormal flow pattern of the splenic artery. Portal vein phase, using superior mesenteric arteriography, showed portal vein varices and obliteration of the portal trunk. A right hepatic lobectomy was performed. The cut surface of the resected liver revealed a ruptured intrahepatic artery aneurysm with massive hematoma.