A previously healthy 89-year-old man was admitted to our hospital with right upper quadrant pain and mild fever. A diagnosis of cholangitis was suspected based on the patient's physical findings and imaging features. Although he received treatment typical for cholangitis, he suddenly died of shock for unknown reasons two months after disease onset. An autopsy revealed a ruptured hepatic artery aneurysm, which had caused lethal intra-abdominal bleeding. In addition, systemic necrotizing vasculitis of small- and medium-sized arteries was detected, and polyarteritis nodosa (PAN) was diagnosed after the autopsy. Biliary symptoms as the initial manifestation of PAN are extremely rare.