Objective: To determine whether a psychological intervention improves coping, post-concussion symptoms and decreases in-prison infractions in adult males with a history of traumatic brain injury. Design: A single centre, randomised, wait-list, pilot study. Setting: A high security prison in New Zealand. Subjects: Fifty-five adult male participants who had experienced at least one traumatic brain injury in their lifetime (mean age 37.29 +/−9.81 years). Intervention: A manualised ten session, in-person, group based combined Cognitive Behavioural Therapy /Mindfulness Based Stress Reduction intervention versus wait list control. Main measures: The Negative Affect Repair Questionnaire and Rivermead Post-concussion Symptom Questionnaire were completed at baseline, post-intervention (five weeks) and at 12 week follow up. In-prison misconduct charges and negative file notes were reviewed for the previous five weeks at each assessment time point. Results: There was an improvement in the use of calming and distraction strategies in the intervention group from baseline (x̄ = 17.38, SD = 3.57) to post-intervention (x̄ = 18.67, SD = 3.84) and 12-week follow up (x̄ = 18.13, SD = 2.63). Participants in the intervention group had significantly higher negative affect repair on the calming and distractive strategies subscale following completion of the intervention, compared to wait-list controls (F = 4.69, P = 0.04) with a moderate effect size (ηp2 = 0.11). Improvements in use of calming and distractive strategies was not sustained at the twelve-week follow-up (F = 0.87, P = 0.36). There was no-significant improvement on other negative affect subscales or for post-concussion symptoms or decrease in-prison infractions. Conclusion: A manualised psychological intervention may have the potential to facilitate the development of positive coping strategies in prisoners with a history of traumatic brain injury.