Little research has explored the relationship between social influences (e.g., social networks, social support, social norms) and health as related to modifying factors that may contribute to health disparities. This is a cross-sectional analysis of fruit and vegetable intake and physical activity, using baseline data from two cancer prevention studies with working-class, multi-ethnic adults. Several social influence and social contextual variables were associated with fruit and vegetable intake and physical activity in both samples. Fruit and vegetable consumption was associated with social norms and social networks, although different contextual variables also were related to intake across the two samples. Physical activity was associated with social networks, social norms, and competing demands. By examining how key social influence and contextual mediating variables relate to health behaviors, we can learn more about the types of interventions that might be needed to promote sustained health behavior change in this population.