OBJECTIVE To retrospectively evaluate the complications of diagnostic cerebral catheter angiography in 19,826 consecutive patients. METHODS This HIPAA-compliant study had institutional review board approval, with waiver of informed consent. Demographic, procedural, and complication data in 19 826 consecutive patients undergoing diagnostic cerebral angiography at one institution from 1981 through 2003 were retrospectively reviewed. Neurologic, systemic, and local complications were recorded on the basis of clinical follow-up results after each angiographic examination. Events that occurred within 24 hours of angiography were considered to be complications of the procedure. Multivariable analysis was employed to identify patient and procedural factors significantly associated with neurologic complications. RESULTS Neurologic complications occurred in 522 examinations (2.63%), and 27 of these (0.14%) were strokes with permanent disability. Twelve deaths occurred (0.06%). Access-site hematoma was the most common complication overall (4.2%). Factors independently associated with an increased risk of neurologic complication included the indication of atherosclerotic cerebrovascular disease (odds ratio [OR], 2.494), the indication of subarachnoid hemorrhage (OR, 2.523), and the comorbidity of frequent transient ischemic attack (OR, 1.674). Factors independently associated with a decreased risk of neurologic complication were increasing chronologic year in which the procedure was performed (OR, 0.659 per 5-year interval) and involvement of a trainee in the procedure (OR, 0.710). CONCLUSIONS In this review, diagnostic catheter cerebral angiography was found to have relatively low complication rates.