AbstractGamesmanship is built on the principle that winning is everything. School athletes are encouraged to bend the rules wherever possible to gain a competitive advantage over their opponents. Therefore, the objective of this study was to identify the main moral decision-making in sports on behaviours among school athletes. Meanwhile, for the second and third objective of this study was to determine the differences of moral decision–making in sports on behaviours among school athletes between genders and sports. The study involved 220 school athletes who completed the Attitudes to Moral Derived Decision Making in Youth Questionnaire (AMDYSQ), which contains 24 items measuring athletes' moral decision-making in sports. Descriptive analysis was used to identify the main moral decision-making in sports on behaviors among school athletes. For inferential analysis, Independent T-Test was used to test the differences in moral decision-making on behaviors among school athletes between genders. M.....