Volunteers today are a very important element of leisure, recreation and sports. Staging big athletic events, such as the Olympic Games, or local recreational tournaments and youth leagues, would not be feasible without the support of sport volunteers. However, although the significance and contribution of these volunteers is widely recognized, research on volunteerism in sports, recreational or not, is mainly based on concepts and measures derived from studies of volunteers in non-sport sectors. An extensive literature review revealed that the knowledge regarding the internal structure of motivation to volunteer, as well as the demographic profile of the volunteer labor is limited. The purpose of this study was to provide organizers of recreational sport events the information needed to design, market, and implement successful volunteer recruitment programs. Specifically, the study focused on the following goals: (a) to investigate the demographic profile of volunteers for the selected recreational sport event; and (b) to explore the major dimensions of sport volunteerism. The event selected for the purposes of this study was the Florida Gulf Beaches Marathon, a recreational running event with international participation that was held in Clearwater, Florida. From the 220 volunteers that assisted in the organization of the marathon, 179 individuals accepted to review, answer and return the questionnaire distributed on site. To assess the demographic characteristics of the sample, frequency analyses were conducted for all demographic factors. The results revealed that (a) 65% of the volunteers were females; (b) the highest proportion of respondents were between 34 and 45 years old (36.8%); (c) 32% of the volunteers had an annual income between $35,000 and $50,000; and (d) the majority of respondents (85%) were Caucasians. In order to identify and interpret the motivational factors that influence volunteers to offer their services to a recreational sport event, an exploratory factor analysis using a principal-component extraction technique with Varimax rotation was conducted. The results suggested the existence of five motivational factors that were identified as material, leisure, egoistic, purposive and external. A confirmatory factor analytic procedure followed and confirmed the goodness-of-fit of the proposed motivational model. This model should be further evaluated in terms of its effectiveness. Additional research should be conducted taking under consideration the size, location, purpose, composition of volunteer labor, and impact of the recreational sport event on the hosting community.Keyword(s): administration/mgmt, athletics/sports, recreation programming