Given that volunteers perform a diverse range of behaviors aimed at helping distinct causes, a more nuanced understanding of how types of volunteer behaviors are similar and different would enrich both basic and applied perspectives on volunteerism. We created and validated an inventory of individuals' interests in eight different types of volunteering: administrative volunteering, helping animals, interpersonal helping (autonomy or dependency), donating, physical volunteering (built or natural environments), and political volunteering. Grouping these eight types of positions into two general categories (interpersonal and skills-based volunteer positions), we also examined convergent and discriminant validity, linking interest in these positions to constructs from the volunteerism literature (i.e., prosocial personality, volunteer motivations, and volunteer satisfaction). This research demonstrates that volunteer behaviors can be classified into types, certain individuals are interested in different types of volunteer behaviors, and volunteers engaged in behaviors that match their interests express greater volunteer satisfaction.