The purpose of this study was to examine the impact of a universal program to promote positive classroom behavior on students' approaches to learning and early academic skills. Second grade classrooms (N = 39) were randomly assigned to treatment and business-as-usual control conditions. Teachers in intervention classrooms implemented the Social Skills Improvement System Classwide Intervention Program (SSIS-CIP) over a 12-week period. Participating students' (N = 494) engagement, motivation, and academic skills were assessed before and after treatment implementation. Results indicated that students with lower levels of engagement and motivation at pretest experienced significant improvement in these areas after exposure to the SSIS-CIP. Although no significant differences were observed in reading, students receiving supplemental instructional services demonstrated greater gains in mathematics than did their peers in the control condition.