The purpose of the paper is to examine the demographic make-up of volunteers and their motives for participating in a professional tennis event. This study uses a cross-sectional descriptive study to investigate the primary motivation of volunteers from a US Open Series professional tennis event. A MANOVA was also conducted to compare the volunteer motivation factors (purposive, egoistic, leisure, material, external) by demographic factors (gender and age). Volunteers' demographics closely resemble the tennis participation population and are similar to other tournament volunteers in the sport of golf. Volunteers were strongly motivated by material and purposive factors. Gender and age had no significant effect on the motivation to volunteer. The sample being from a single event can limit the generalizations, but the work can serve as a framework for more extensive studies, including focusing on a women's event to examine the differences in motivation. Implications of the results are provided in an effort to assist sport managers to design quality volunteer experiences that enhance the overall experience, supporting episodic volunteers' work ethic, and management of the event. There is clear evidence that volunteer satisfaction is higher when their motives are met. It is intended that this research will offer more support for event organizers based on the growing usage of volunteers and concerns in the sport industry. This study is the only one that examines tennis volunteers in general as well as exploring the effect of the dependent variables of gender and age on motivation.