Background: Persons with multiple sclerosis (MS) are often physically inactive and sedentary. This observation has prompted the search for modifiable variables derived from established theories that act as correlates of physical activity. Such variables would presumably represent targets for interventions designed to promote change in physical activity behavior among persons with MS. The current study examined social cognitive variables as correlates of physical activity in persons with MS. Methods: Persons (N = 218) with relapsingremitting MS completed a questionnaire battery that assessed physical activity behavior; self-efficacy for physical activity; physical, social, and self-evaluative outcome expectations for exercise, functional limitations as an impediment for physical activity, and exercise goal-setting. The battery was delivered and returned through the US postal service. Data were analyzed using covariance modeling in Mplus 3.0. Results: Self-efficacy had indirect effects on physical activity via impediments (path coefficient = .10, P < .005), self-evaluative outcome expectations (path coefficient = .07, P < .025), and goal-setting (path coefficient = .09, P < .01). The model explained 40% of variance in self-reported physical activity. Conclusions: This cross-sectional study suggests that self-efficacy is indirectly associated with physical activity by way of goals, self-evaluative outcome expectations, and impediments in persons with relapsing-remitting MS. © 2011 Human Kinetics, Inc.