This report summarizes the Walter Reed Army Medical Center experience with six patients operated on from 1949 through 1982 for vascular injury related to lumbar disk surgery. All had common iliac artery injuries generated by L4-5 disk operations. Four patients had isolated arterial injuries and two had combined arteriovenous injuries. Three underwent vascular repair acutely, two with shock and one with a false aneurysm. Delay in diagnosis occurred in two patients who presented 6 weeks and 3 years postinjury with minimally symptomatic arteriovenous fistulae. A sixth patient had a known arterial injury and was operated on after a 1-month delay. All patients survived. Two patients had had repeated back operations, suggesting that this may be a risk factor for perforation of the anterior spinal ligament by an operative rongeur.