Objective: The optimization of long-term outcomes is an important goal in the treatment of major depressive disorder. Offering subsequent preventive cognitive therapy (PCT) to patients who responded to acute cognitive behavioral therapy (CBT) may reduce the risk of relapse/recurrence. Method: Therefore, a multicenter randomized controlled trial was conducted comparing the addition of eight weekly sessions of PCT to care as usual (CAU) versus CAU alone in patients with a history of depression in remission following treatment with CBT. A total of 214 recurrently depressed patients who remitted following treatment with CBT were randomized to PCT (n = 107) or CAU (n = 107). Primary outcome was time to relapse/recurrence over 15 months and was assessed by the Structured Clinical Interview for DSM-IV Axis I Disorders (SCID-I). Secondary outcomes were depressive symptoms measured by the Inventory of Depressive Symptomatology- Self Report and number and severity of relapses/recurrences measured by the SCID-I. Results: Over the 15-month follow-up, the addition of PCT significantly delayed time to relapse/recurrence relative to CAU alone, hazard ratio = 1.807 (number needed to treat = 8.1), p = .02, 95% CI [1.029, 3.174]. No significant differences were found between the conditions on number or severity of relapses/recurrences and residual symptoms. Conclusion: Adding PCT was significantly more effective than CAU alone in delaying time to relapse/recurrence of depression over a period of 15 months among CBT responders. After response on CBT, therapists should consider providing PCT to recurrently depressed patients.