We recently experienced a case of vascular injury detected three days after lumbar disk surgery. CT accurately depicted a false aneurysm of left common iliac artery as well as massive retroperitoneal hemorrhage. CT alsocorrectly predicted the accompanying venous injury by observing poorly identified left common iliac vein and smallair pockets. Angiography confirmed the false aneurysm, unassociated with an arteriovenous fistula. The patient underwent vascular surgery, and did well thereafter, We think awareness of vascular complications related to diskoperation is quite important for diagnosis and management of these tragic events.