Treatment non-adherence is a common problem in mental health services but little is known about non-adherence to psychological therapy for psychosis. The main aim of the present study was to investigate the role of patients' recovery style and the therapeutic alliance in provoking or forestalling patient drop-out from cognitive behaviour therapy (CBT) for psychosis. Ratings were made by two independent observers on 29 recordings of sessions from a controlled trial of CBT for psychosis. Sessions of 10 patients who dropped out of treatment prematurely were matched with sessions of 10 patients who stayed in. Another nine sessions were selected at random from the middle and late stages of treatment so that the sample was representative of all sessions in the trial. Patients who dropped out of treatment, compared with those who stayed in, were less engaged in treatment, showed less agreement with their therapists, and had a sealing-over recovery style before they dropped out but did not differ in their therapeutic bonds. The results suggest that the premature termination of the drop-outs was not provoked by the therapists but was due to the patients' lack of curiosity about their psychotic episodes and minimization of the impact of their illness.