Although the efficacy of maintenance pharmacotherapy for the prevention of recurrence in major depressive disorder (MDD) is well documented, few studies have tested the efficacy of psychotherapy as a maintenance treatment. The authors examined the efficacy of the cognitive-behavioral analysis system of psychotherapy (CBASP) as a maintenance treatment for chronic forms of MDD. Eighty-two patients who had responded to acute and continuation phase CBASP were randomized to monthly CBASP or assessment only for 1 year. Significantly fewer patients in the CBASP than assessment only condition experienced a recurrence. The 2 conditions also differed significantly on change in depressive symptoms over time. These findings support the use of CBASP as a maintenance treatment for chronic forms of MDD.