This study compared the efficacy and tolerability of 150 mg/day imipramine and 50 mg/day sertraline for the treatment of a major depressive episode (DSM-IV) in older adults (N = 55) in an 8-week, randomized, double-blind, controlled clinical trial. Intention-to-treat analysis (last observation carried forwards) showed a reduction of 50% or more on the baseline scores of the Montgomery-Åsberg Rating Scale (MADRS) in 60.7% and 55.6% of patients receiving imipramine and sertraline, respectively (p = .698). Full remission of symptoms (MADRS < 9) was observed in 50.0% and 51.8% of patients, respectively (p = .891). Side effects were more frequent among patients treated with imipramine (86.7%) than among patients treated with sertraline (42.1%) (p = .008). Dropout rates were high in both groups (46.4% and 29.6% respectively, p = .200). These results indicate that imipramine and sertraline are equally effective for the treatment of major depression in later life, although adverse reactions are more frequent among subjects treated with imipramine than with sertraline.