ABSTRACT This study examines the effect of role ambiguity on volunteer job performance and investigates the mediating roles of role ambiguity between two social exchange qualities (i.e., team-member exchange and leader-member exchange) and job performance in reducing the negative effect of role ambiguity on job performance. Data were collected from volunteers at charity sport events in the U.S. Hypotheses were tested by using Hayes PROCESS macro model 1 and 4 for SPSS. The study found that role ambiguity is negatively related to job performance and that team-member exchange and leader-member exchange indirectly influence job performance through the mediating mechanism of role ambiguity. Also, the moderating effect of gender on the relationship between role ambiguity and job performance was found. Theoretical and practical implications for charity sport event volunteers, as well as recommendations for future research, are presented.