Objective: There is growing evidence to support the short-term antidepressant effects of repetitive transcranial magnetic stimulation (rTMS), but few published data pertain to the maintenance treatment of patients with DSM-IV-diagnosed major depressive disorder who have responded acutely to rTMS. We describe long-term maintenance therapy for major depressive disorder with rTMS. Method: Repetitive transcranial magnetic stimulation was applied in 10 adults over the left prefrontal cortex at 100% of motor threshold, most often at a frequency of 10 Hz for sessions consisting of 40 trains at 5 seconds per train (2000 pulses per session), for periods ranging from 6 months to 6 years. Session frequency averaged 1 to 2 per week. The study was conducted in the TMS lab of an academic medical center. Results: Seven of the 10 subjects experienced either marked or moderate benefit, which was sustained without the addition of concomitant antidepressant medication in 3 cases. There were no serious adverse events reported by any participant. The seizure rate for the 1831 reported rTMS sessions was zero. Conclusions: These data, while open label, suggest that maintenance rTMS may be a safe and effective treatment modality in some patients with unipolar depression. Further research into the long-term safety and efficacy of rTMS is warranted.