Objective To examine the effectiveness of a cognitive–behavioural therapy (CBT) group intervention to facilitate improved psycho‐sexual adjustment to treatment side effects in prostate cancer survivors post‐radical prostatectomy. Methods A randomised, wait‐list controlled trial was conducted with a total of 60 men who participated in a manualised 8‐week cognitive–behavioural group intervention 6 months to 5 years post‐radical prostatectomy for localised prostate cancer. Participants completed standardised questionnaires pre‐intervention and post‐intervention, which assessed mood state, stress, general and prostate cancer anxiety, quality of life and areas of sexual functioning. Results Paired samples t‐tests identified a significant improvement in sexual confidence, masculine self‐esteem, sexual drive/relationship and a significant decline in sexual behaviour from pre‐intervention to post‐intervention. Hierarchical regression analyses revealed that after controlling for covariates, participation in the group intervention significantly improved sexual confidence, sexual intimacy, masculine self‐esteem and satisfaction with orgasm. Conclusions This group‐based CBT intervention for men post‐radical prostatectomy for localised prostate cancer shows promising results in terms of improving quality of life. Copyright © 2013 John Wiley & Sons, Ltd.