The purpose of this study was to identify factors underlying decisions to participate in work-site wellness programs. A sample of 279 full-time workers from a service division of a rural Midwestern university completed a survey assessing demographic and job characteristics, health status and health behaviors, and Reasoned Action Approach (RAA) variables for participating in work-site wellness activities. Regression analyses identified factors associated with intention; multivariate analyses of variance compared low to high intenders on salient beliefs. In sequential regression analyses, constructs of RAA predicted intention over and above the three significant background variables of age, exercise in past month, and fruit and vegetable consumption (R[superscript 2] = 0.469, R[superscript 2] change = 0.409, p less than 0.001). Attitude had the highest relative weight (beta = 0.445, p less than 0.001); perceived norm had a significant weight (beta = 0.273, p less than 0.001). Significant differences in beliefs were found. To increase participation, planners should design programs that provide benefits employees perceive as advantageous and ensure coworker and supervisor support. (Contains 4 tables.)