We compared the effectiveness of three anaesthetic regimens (propofol alone, propofol with remifentanil and sevoflurane alone), with respect to seizure duration and seizure quality in patients undergoing electroconvulsive therapy. Thirty-nine patients underwent a total of 234 electroconvulsive therapy treatments in this prospective, observer blinded, crossover study. Each patient received either propofol 1 mg/kg alone (Group P), propofol 0.5 mg/kg and remifentanil 1 µg/kg (Group R), or sevoflurane alone 6% (Group S) for their initial electroconvulsive therapy session. The patients subsequently received an alternative regimen in their next session, such as from propofol 1 mg/kg alone to propofol 0.5 mg/kg and remifentanil 1 µg/kg, from propofol 0.5 mg/kg and remifentanil 1 µg/kg to sevoflurane alone 6%, or from sevoflurane alone 6% to a continuing alternation between drugs at each session, until their sixth session. Muscle paralysis was achieved with 1 mg/kg succinylcholine. Seizure duration, postictal suppression index, early and midictal amplitude were recorded. The mean motor and electroencephalogram seizure durations were significantly longer in Groups P and R compared to Group S (P <0.001). The postictal suppression index and early and midictal amplitude values were not significantly different among the groups. These findings indicate that the three anaesthetic regimens had similar effects on seizure quality parameters, although sevoflurane was associated with shorter seizure durations than propofol or propofol-remifentanil.