Background: Anger causes significant problems in offenders and to date few interventions have been described in the Caribbean region. Aim: To evaluate a package of CBT-based Anger Management Training provided to offenders in prison in Trinidad. Method: A controlled clinical trial with 85 participants who participated in a 12-week prison-based group anger management programme, of whom 57 (67%: 16 control, 41 intervention) provided pretrial and posttrial outcome data at Times 1 and 2. Results: Intervention and control groups were not directly comparable so outcome was analysed using t-tests. Reductions were noted for state and trait anger and anger expression, with an increase in coping skills for the intervention group. No changes were noted in the control group. The improvements seen on intervention were maintained at 4 month follow-up for a sub-group of participants for whom data were available. Several predictors of outcomes were identified.