Forty-eight unipolar depressed patients were randomly assigned to 12 weeks of treatment with either imipramine (IMI) (n = 32) or cognitive therapy (CT) (n = 16). Prior to treatment assignment, all patients were rated for severity of a variety of psychosocial stressors. The interaction effect between pretreatment stress and type of treatment, CT or IMI, on symptom improvement was evaluated. We hypothesized that patients with greater pretreatment stress would respond better to cognitive therapy. Patients treated with either CT or IMI showed equivalent reductions of depressive symptoms. There was no interaction effect between pretreatment stress and type of treatment on improvement of depressive symptoms. Based on this preliminary study it does not appear that depressed patients with higher pretreatment levels of stress respond better to cognitive therapy than they do to imipramine.