High frequency left-sided and low frequency right-sided unilateral repetitive transcranial magnetic stimulation are efficacious in treatment-resistant major depression. Similar benefit has been suggested for sequential bilateral rtms. There are few published reports on the efficacy of sequential bilateral rtms compared to hft and sham rtms. Therefore, this study evaluated the efficacy of HFL and sequential bilateral rtms compared to sham in trd. Methods. Subjects between the ages of 18 and 85 were recruited from a tertiary care university hospital. Seventy-four subjects with trd and a 17-item Hamilton Depression Rating Scale greater than 21 were randomized to receive unilateral, bilateral, or sham rtms. The rates of remission were compared among the three treatment groups. The remission rates differed significantly among the three treatment groups using a modified intention to treat analysis that excluded subjects who did not respond to electroconvulsive therapy during the current episode. The remission rate was significantly higher in the bilateral group than the sham group. The remission rate in the unilateral group did not differ from either group. These findings warrant larger controlled studies that compare the efficacy of sequential bilateral rtms and hfl rtms in trd.