This study represents an attempt to evaluate Barkham and Shapiro's (1988) two-plus-one model of brief psychotherapy with a young offender population as a way of significantly improving service delivery for clinical teams working in prisons. Brief cognitive-behavioural interventions were administered to young offenders referred for problems with depression, alcohol and anger whilst in custody. Significant treatment effects were found at the time of follow-up, suggesting that the interventions significantly accelerated improvement in these problem areas. It is suggested that the two-plus-one model is both an appropriate and effective model of service delivery in working with this client group.