OBJECTIVE To examine the clinical practice of right unilateral electroconvulsive therapy (ECT) administered at six times seizure threshold (6 x RUL ECT). METHODS A retrospective review of all patients who received 6 x RUL ECT between July 2000 and June 2002. RESULTS Twenty-one patients across a range of ages and diagnostic groups received D'Elia unilateral ECT at a seizure dosage at or above 388.8 milliCoumbs (mC). In order to sustain predetermined criteria for seizure adequacy, energy was increased in 71% of patients. Final seizure lengths of 45 s electroencephalographic (EEG) activity, 28 s motor activity (cuffed) and a post-ictal suppression index (PSI) of 83% were recorded. Eighty percent of patients responded after a mean of 7.0 treatments. Cognitive side-effects were noted in 21% of patients. Fifty-two percent relapsed on average 6.3 months after the last treatment despite continuation pharmacotherapy. CONCLUSIONS 6 x RUL ECT was found to be clinically effective, associated with cognitive side-effects and relapse. The debate over electrode placement is likely to continue.