This report presents findings from a study commissioned by the Australian Sports Commission to investigate whether sport and organised physical activity programs have a positive effect on youth antisocial behaviour. The AIC identified and surveyed over 600 programs focusing on sport and physical activity. In-depth case studies of 22 of these programs identified important elements for preventing youth antisocial behaviour. The research evidence suggests that sport and physical activity programs can provide a useful vehicle through which personal and social development may occur and positively impact antisocial behaviour. Providing an activity may be more important than the type of activity provided as a mechanism for diverting youth away from antisocial behaviour. The report highlights the importance of sport and physical activity programs being integrated with health, welfare and other support services, and also sets out good practice principles for the development of such programs.