It is believed that the social connections formed by participating in physical activity-based positive youth development (PYD) programs contributes to building personal and social assets. In this study, we examined how changes in social connection over a physical activity-based PYD program for low-income youth were associated with changes in psychological outcomes. Participants (N = 197) completed pre- and postprogram questionnaires assessing leader support, social competence, physical competence, and psychological outcomes (global self-worth, physical self-worth, attraction to physical activity, and hope). Social competence, physical competence, physical self-worth, and global self-worth increased significantly over the 4-week program. Changes in social connections predicted changes in psychological outcomes. Effect sizes were modest but suggest that social interventions hold potential to promote positive outcomes in underserved youth. (Contains 3 tables.)