This study investigated sex differences in observed prosocial and antisocial behaviors in soccer and the role of personal and social factors in explaining these differences. Male (n = 26) and female (n = 20) soccer teams, consisting of players (N = 464) whose age ranged from 15-47 years, participated in the study. For each team, a 90-min soccer game was videotaped, and questionnaires were administered to players measuring empathy, motivational climate, soccer experience, and demographics. Two observers recorded prosocial and antisocial behaviors for each team. Analysis of variance (ANOVA) indicated that males and females did not differ in prosocial behaviors, but males engaged in more antisocial acts than females. Analysis of covariance (ANCOVA) showed that the effects of sex on antisocial behavior were substantially reduced when behavior scores were adjusted for empathy, perceived performance climate, or soccer experience. Our findings underscore the importance of these variables in explaining sex differences in antisocial behavior in soccer.