Many patients who receive electroconvulsive therapy (ECT) are benzodiazepine dependent or are anxious and require benzodiazepine drugs. Because these agents may diminish the therapeutic effectiveness of ECT, we explored the dosing, safety, and efficacy of pre-ECT flumazenil administration, a benzodiazepine-competitive antagonist, in patients receiving benzodiazepine medications. We report our experience with 35 patients who received both flumazenil and benzodiazepine drugs during their ECT course. We compared seizure duration with and without flumazenil and compared treatment efficacy to 49 patients who received ECT without either of these medications. Flumazenil could be safely administered with ECT. A few subjects taking higher chronic benzodiazepine dosages experienced breakthrough anxiety or withdrawal symptoms, which were well managed by dosing flumazenil immediately before the anesthetic agent and by immediate posttreatment benzodiazepine administration. A dose of 0.4–0.5 mg was adequate for all but those taking the highest benzodiazepine dosages, where 0.8–1.0 mg resulted in a clinically more effective reversal. No differences in efficacy or seizure duration were found as a function of flumazenil administration. Flumazenil offers the promise of safe and effective ECT in patients receiving benzodiazepine drugs. Follow-up outcome investigation on a random assignment basis will be necessary for definitive assessment of the value of flumazenil. In addition, the direct effect of benzodiazepine drugs and the flumazenil/benzodiazepine combination on ECT seizures remains to be determined.