Background The efficacy of cognitive–behavioural therapy for schizophrenia is established, butthere is less evidence for a group format. Aims To evaluate the effectiveness of group cognitive–behavioural therapy for schizophrenia. Method In all, 113 people with persistent positive symptoms of schizophrenia were assigned to receive group cognitive–behavioural therapy or treatment as usual. The primary outcome was positive symptom improvement on the Positive and Negative Syndrome Scales. Secondary outcome measures included symptoms, functioning, relapses, hopelessness and self-esteem. Results There were no significant differences between the cognitive–behavioural therapy and treatment as usual on measures of symptoms or functioning or relapse, but group cognitive–behavioural therapy treatment resulted in reductions in feelings of hopelessness and in low self-esteem. Conclusions Although group cognitive–behavioural therapy may not be the optimum treatment method for reducing hallucinations and delusions, it may have important benefits, including feeling less negative about oneself and less hopeless for the future.