Previous studies have suggested that human resource practices implemented by nonprofit organizations can enhance volunteer attitudes and behaviors. We contribute to this stream of research by developing and testing a model whereby the relationship between human resource practices and volunteer engagement is mediated by volunteers’ identification with their organization and their level of empowerment. The data (n=229 volunteers), sourced from six nonprofit organizations in the Netherlands, confirm our theoretical model, in that volunteers’ perceptions of human resource practices are positively related to their level of engagement via both mediators. The study contributes to the development of engagement theory for the volunteering context, by extending knowledge on its antecedents, and it therefore highlights organizational mechanisms suitable for volunteers, which benefit nonprofit organizations and volunteers alike.