Inpatient and outpatient cognitive behavioural pain management programmes for mixed chronic pain patients were compared. Patients were randomly allocated to the 4 week inpatient programme or to the 8 half day per week outpatient programme, or to a waiting list control group. Staff, teaching materials, and setting were the same for the two treatment groups. Patients were assessed pre-treatment, and at 1 month after discharge, and treated patients also at 6 months and 1 year after discharge, by assessors blind to treatment group; assessments included physical, functional and psychological measures, and medication use. In total, 121 mixed chronic pain patients (mean age 50 years; mean chronicity 8.1 years) were included in the study, following medical examination to ensure that no further medical treatment was appropriate. There was no change in the control group; inpatients and outpatients, comparable before treatment, both made significant improvements in physical performance and psychological function, and reduced medication use. Inpatients made greater gains, and maintained them better at 1 year; they also used less health care than outpatients. There were no outstanding predictors of improvement other than treatment group.