Motherhood is associated with low rates of physical activity that increase disease risk. Most theory-based approaches to increasing physical activity focus on personal rather than social factors. The purpose of this study was to examine the associations among perceptions of community collective efficacy and objectively measured physical activity, self-efficacy, social support, and health. Mothers completed questionnaires and wore a pedometer for 7 days. There was a significant, positive association between physical activity and collective efficacy-social cohesion subscale. In the regression analysis, only age and social support were independent predictors of physical activity. Future studies should examine relationships among collective efficacy and social support and physical activity.