Intraoperative angiography in carotid extracranial surgery demonstrates technical defects in 5% to 8% of patients. A simple and safe method of completion contact angiography (CCA) has been perfected by adapting dental x-ray equipment, small dental film cassettes, and a "shoe box" type of developing unit. The method is not technician dependent, requires only 5 ml of contrast medium, has a completion time of less than 5 minutes, and produces no measurable radiation to the operating team. CCA was performed with no complications in 40 patients undergoing carotid endarterectomy. Two unsuspected internal carotid artery defects (5%) were discovered: in one a stenosis was immediately repaired, and in the other small thrombi that were seen but not removed were probably the cause of a postoperative transient ischemic attack. Two complete occlusions and one prominent intimal flap in the external carotid artery were also identified. We believe that CCA after carotid surgery should be used routinely because it is safe and simple and reveals unsuspected operative defects that can be corrected immediately.