OBJECTIVE A retrospective study was conducted to evaluate clinical usefulness of video EEG monitoring in patients with suspected epileptic seizures. METHODS A total of 444 patients who had diagnostic video EEG from January 1989 to December 1992 were studied after excluding those with known medically refractory focal epilepsy undergoing presurgical evaluation. Most were outpatients and had video EEG monitoring during normal working hours over 1-5 days. RESULTS The procedure had a success rate of 73%; characteristic events were captured and categorized in 53% of the patients. Patients with an event frequency of at least one per week or those who had events characterized by motor manifestations showed a higher yield. Thirty-two percent of the patients had psychogenic seizures. Thirty-four percent of the patients had either epileptic seizures recorded during the study or showed clear-cut interictal epileptiform abnormalities providing strong evidence of underlying epileptic process. CONCLUSIONS In patients with frequent paroxysmal events, a video EEG study provides diagnostically critical information. It can be performed usually as an outpatient investigation.