Extracorporeal shock wave lithotripsy (ESWL) represents the preferred treatment for most upper ureteric and renal calculi. Complication rates associated with ESWL are low, justifying the enthusiasm and acceptance of this treatment modality. We report a case of abdominal aortic pseudoaneurysm due to ESWL. A 47-year-old man had undergone ESWL treatment for ureteric calculi since 1990. He was admitted to our hospital because of lumbar pain. Physical examination revealed a pulsatile mass in his abdomen. Abdominal CT scan showed an abdominal aortic aneurysm (5.3cm in diameter). Angiography showed a fusiform aneurysm of the infrarenal abdominal aorta. Y-graft replacement was performed after aneurysm resection. Histological examination revealed that it was a pseudoaneurysm. The patient had no history of trauma, inflammation or operation except ESWL. This is the first report of abdominal aortic pseudoaneurysm due to ESWL.