This research uses social role theory to investigate gender differences in volunteers at the Special Olympics and interrelationships among motivations, commitment, and social capital. Volunteers at the 2014 National Summer Special Olympics in Germany were surveyed (n = 891). Multigroup structural equation modeling has revealed gender differences among motivations, commitment, and social capital. Volunteers primarily volunteered for personal growth. Further, motivations had a significant association with commitment and social capital. The impact of motivation on social capital was significantly mediated by commitment. Event organizers should market opportunities to volunteer by emphasizing opportunities for personal growth and appealing to specific values.