The nature and scope of volunteer involvement in sport is well established, however research indicates that involvement in community sport volunteering is under threat (Cuskelly, 2005; Cuskelly, Taylor, Hoye & Darcy, 2005). Trends indicate volunteer hours per individual are decreasing and this can have significant implications for the successful operation of voluntary sport organizations and the subsequent benefits for participants and the communities in which they operate. This paper extends knowledge of the nature of volunteer engagement in sport by exploring the categorization of sport volunteers as "core" or "peripheral" based on self-reported levels of involvement and commitment within Voluntary Sport Organizations (VSO). Using a survey of 243 sport volunteers across three sports, we identified significant differences between core and peripheral volunteers based on their levels of involvement and commitment in their self-identified primary sport organization roles. Implications of these findings for volunteer recruitment and retention, and for the provision of sport participation opportunities in the community are addressed.