Patients' beliefs about depression and expectations for treatment can influence outcomes of major depressive disorder (MDD) treatments. We hypothesized that patients with weaker biological beliefs (less endorsement of (a) biochemical causes and (b) need for medication), and more optimistic treatment expectations (greater improvement and shorter time to improvement), have better outcomes in cognitive therapy (CT). Outpatients with recurrent MDD who received acutephase CT (N = 152), and a subset of partial or unstable responders (N = 51) randomized to 8 months of continuation CT or fluoxetine with clinical management, completed repeated measures of beliefs, expectations, and depression. As hypothesized, patients with weaker biological beliefs about depression, and patients who expected a shorter time to improvement, experienced greater change in depressive symptoms and more frequent response to acute-phase CT. Moreover, responders who received continuation treatment better matched to their biological beliefs (i.e., responders with weaker biological beliefs about depression who received continuation CT, or responders with stronger biological beliefs about depression who received continuation fluoxetine)