The effectiveness of conflict resolution and peer mediation (CRPM) training among 10- and 11-year-old elementary school students was examined. The CRPM training program consisted of skills, such as understanding the nature of interpersonal conflicts, communication, anger management, negotiation and peer mediation. The research was carried out using pretest/posttest-quasi-experimental design. The sample included 591 students; 326 in the experiment and 265 in the control group. A self-report questionnaire which consisted of four subscales (integrative/constructive, smoothing, forcing and withdrawing/avoidance) was used to collect data related to conflict resolution strategies. The CRPM training program significantly improved students' "integrative/constructive" conflict resolution strategy and reduced their "forcing" and "withdrawing/avoidance" strategies. However, no statistically significant difference was found in the "smoothing" strategy. When boys' and girls' results were examined separately, boys' "integrative/constructive" conflict resolution strategy scores increased after the training, while their "forcing" scores decreased. CRPM training was not found to be effective in girls. (Contains 2 tables.)