Metacognitive Therapy (MCT) for depression is a formulation-driven treatment grounded in the Wells and Matthews (Attention and emotion: A clinical perspective, 1994) self-regulatory model. Unlike traditional CBT it does not focus on challenging the content of depressive thoughts or on increasing mastery and pleasure. Instead it focuses on reducing unhelpful cognitive processes and facilitates metacognitive modes of processing. MCT enables patients to interrupt rumination, reduce unhelpful self-monitoring tendencies, and establish more adaptive styles of responding to thoughts and feelings. An important component of treatment is modification of positive and negative metacognitive beliefs about rumination. MCT was evaluated in 6–8 sessions of up to 1 h each across 4 patients with recurrent and/or chronic major depressive disorder. A non-concurrent multiple-baseline with follow-up at 3 and 6 months was used. Patients were randomly allocated to different length baselines and outcomes were assessed via self-report and assessor ratings. Treatment was associated with large and clinically significant improvements in depressive symptoms, rumination and metacognitive beliefs and gains were maintained over follow-up. The small number of cases limits generalisability but continued evaluation of this new brief treatment is clearly indicated.