This study explored individual, family, and peer predictors of involvement and psychological investment in fights among Samoan youth. Participants were 310 adolescents ages 13 through 19 living in Samoa. MANCOVAs compared those involved in fights with those not, and those more investing in fighting with those less invested. In terms of individual predictors, for both of the independent variables groups differed on school engagement, religiosity, proactive aggression, reactive aggression, moral disengagement, and social dominance but not self-regulation, empathy, or moral identity. Groups also differed on all peer variables: proactive aggression, reactive aggression, fight investment, and fight involvement. For involvement, groups differed on maternal and paternal psychological control and disrespect, but not parental monitoring. For investment, there were no differences on family variables. Path models found proactive aggression and peer fight involvement predictive of involvement, and proactive aggression, moral disengagement, peer investment, and maternal psychological control predictive of investment.