Sport is generally presented as a relevant way of promoting ethics, in particular for children and young adults. However, one is more often confronted in media with unethical behaviours, transgressing sports rules, than with fair play behaviours. It seems important to identify which factors are likely to influence these behaviours, in order to target more specific and relevant forms of action (Kavusssanu & Boardley, 2009). The role of the coaches often appears to be important, because they constitute models, in particular for the youngest players. In another way, values are general principles that guide behaviour across different social situations. So, they should underpin decision making in sport, specifically those pertaining to achievement and morality. Evaluating sports-related values among players seems unavoidable when one is interested in sporting ethics (Lee, Whitehaed, N’Toumanis, & Hatzigeorgiadis, 2008). The aim of this study is to analyse pro-social and anti-social behaviours implemented by players in soccer and rugby and to identify the role of their sport-related values and their perception of the coaches’ behaviours Methods : 421 soccer players and 164 rugby players were included in the study. Questionnaires measuring sport values, anti-social and pro-social behaviours declared by players, and anti-social and pro-social behaviours of coaches perceived by players were used. Results and Discussion : The main results revealed first that status-related values, as well as anti-social behaviours of coaches, were significant predictors of anti-social behaviours declared by players. But a significant effect of type of sport (soccer/rugby) was also observed for moral-related values and anti-social behaviours of players and coaches. Finally, significant differences were revealed according to the target of anti-social and pro-social behaviours (opponent, teammate, referee). Conclusions : This study provides evidence indicating the fundamental role played by coaches in the regulation of ethics behaviours in sport.