Rule breaking behavior in sports (e.g., fouls) can impact the outcome of games, tournaments, or even whole seasons. Although personality traits have been related to different forms of rule breaking behavior across fields, it has hardly been investigated whether personality traits predict rule breaking behavior in sports. We ran a longitudinal study with 242 (semi-)professional basketball players. Specifically, we measured personality traits prior to the start of the season and official foul statistics per player during the season. Out of the basic personality traits from the HEXACO Model of Personality, Conscientiousness accounted for a substantial amount of variability in the committed/called fouls, whereas no robust relations with other traits or a sports-oriented personality trait (i.e., Sports Mental Toughness) were found.