The aim of the study was to determine whether depressed aged inpatients treated with brief pulse unilateral electroconvulsive therapy (ECT) differed from those treated with bilateral (bitemporal or bifrontal) ECT with respect to numbers of treatments, length of hospital admission, changes in scores on depression and cognitive scales, and serious adverse effects. An audit of routinely collected data regarding 221 acute ECT courses in 7 public aged psychiatry services in Victoria, Australia. Patients given unilateral, bifrontal, and bitemporal treatments were similar with respect to personal, clinical, and treatment characteristics. Most treatments were administered in line with local clinical guidelines and were rated as effective. Psychiatrists preferred unilateral ECT in the first instance with stimulus dosing based on patients' seizure thresholds. Approximately a quarter of unilateral courses were switched later to bitemporal placement, most probably because of insufficient progress. Bilateral treatments were associated with a larger number of treatments, less improvement in scores on mood and cognitive scales, and more refusals to continue treatment than unilateral-only ECT. Brief pulse unilateral ECT proved more effective than bitemporal and bifrontal ECT for most aged patients, especially when coupled with stimulus dosing based on seizure threshold.