Objectives: The study examined the effects of the Self-Management Training and Regulation Strategy (STARS) on disruptive behavior, authority acceptance, social competency, and student–teacher relations. Method: All fourth- and fifth-grade students (N = 762) in seven schools and 42 classrooms were screened for disruptive behaviors. Using a cluster randomized design, 60 students in 23 classrooms and 48 students in 19 classrooms with highest levels of disruptive classroom behaviors were randomized to STARS or a control comparison condition. Multilevel models compared study conditions on all outcomes. Results: Study conditions were balanced at pretest. STARS students demonstrated improved teacher-rated disruptive behavior, social competence, authority acceptance, and relations. Conclusions: Selective programs targeting autonomy support improve social competencies and relationships that are important for school success.