This study was performed to determine the effects of a stress management training program that was administered to adolescents in prison. This was a semi-experimental study that used pretests and posttests in controlled groups; it was performed between June 2012 and March 2013 in a closed prison for children and adolescents. The study was completed with the participation of 73 adolescents (36 in the experimental group and 37 in the control group). Adolescent Lifestyle Profile scale and the Stress Coping Styles Scale were used as the data collection tools. The Stress Management Training Program was developed by the researchers and carried out for 2weeks, a total of 10 sessions of 40min each. The scales were administered before the program was implemented, immediately after the program and 1month following the program. Although there were no statistically significant differences between the mean Stress Coping Styles Scale scores of the experimental and control groups before the intervention (p>0.05), a statistically significant difference was found after the intervention and at re-test (p<0.05). This study has shown that this training program could be implemented with adolescents in prison, and the program was effective in providing positive behavioural changes in stress management. Copyright (c) 2016 John Wiley & Sons, Ltd.