This study examined the effects of personal accountability and personal responsibility instructional treatments on elementary-age, urban, at-risk physical education students. A multiple treatment (ABAD, ACAD, ADA, control) behavior-analysis design was implemented across four distinct matched class settings to determine the separate and combined treatment effects of each instructional treatment on the number of occurrences and percentage of class time for the following: teacher management, student leadership, passive and disruptive student off-task, positive social, and student conflict and conflict resolution behaviors. Study participants included fourth- and fifth-grade students from four elementary classes in an inner-city charter-school setting. Results indicated that both personal accountability and personal responsibility treatments were effective in the primary treatment setting for changing all managerial, off-task, and positive social measures in desirable directions with the personal responsibility treatment particularly effective with more complex behaviors of positive social behavior and student conflict resolution. Recommendations include analysis of the potential long-range and generalized effects of social-skill instruction for underserved children and youth conducted in the context of physical education classes. (Contains 4 tables and 5 figures.)