A randomized clinical trial was undertaken to investigate the relative efficacy of rational-emotive behavior therapy (REBT), cognitive therapy (CT), and pharmacotherapy in the treatment of 170 outpatients with nonpsychotic major depressive disorder. The patients were randomly assigned to one of the following: 14 weeks of REBT, 14 weeks of CT, or 14 weeks of pharmacotherapy (fluoxetine). The outcome measures used were the Hamilton Rating Scale for Depression and the Beck Depression Inventory. No differences among treatment conditions at posttest were observed. A larger effect of REBT (significant) and CT (nonsignificant) over pharmacotherapy at 6 months follow-up was noted on the Hamilton Rating Scale for Depression only. © 2008 Wiley Periodicals, Inc. J Clin Psychol 64:728-746, 2008.