A comparison of methohexital at 0.5 mg/kg versus 1 mg/kg iv as anesthesia for unilateral brief pulse electroconvulsive therapy showed no difference in systolic or diastolic blood pressure before, immediately after, or 5 or 10 min after the seizure. Mean seizure duration was not significantly shorter using the higher methohexital dosage. These results show that methohexital can be safely used in a broad dosage range without undue effects on blood pressure or seizure duration.