School-Wide Positive Behavioral Interventions and Supports (SWPBIS; Sugai & Horner, 2006) is currently implemented in over 20,000 schools across the country with the goal of preventing disruptive behavior problems and enhancing the school climate. While previous studies have indicated significant main effects of SWPBIS on student outcomes, the program impacts likely vary as a function of children's social-emotional characteristics. This study examined variation in the effects of SWPBIS based on children's baseline pattern of behavior problems and social-emotional skills using data from a randomized controlled effectiveness trial. Data come from 12,344 elementary school children (52.9% male; 45.1% African American and 46.1% White; 49% received free or reduced-price meals; and 12.9% received special education services). The group randomized controlled effectiveness trial was implemented in 37 elementary schools. Latent profile analyses (LPA) were conducted on teachers' baseline ratings of children's behavior problems, concentration problems, social-emotional functioning, and prosocial behavior using the Teacher Observation of Classroom Adaptation-Checklist (TOCA-C; Koth, Bradshaw, & Leaf, 2009). LPA revealed 4 latent classes: high-risk (6.6%), at-risk (23.3%), normative (36.5%), and socially-emotionally skilled (33.6%). LPA membership was found to have a moderating impact on children's subsequent discipline problems and need for and use of school-based services. Findings suggest that the effects of SWPBIS on student outcomes tend to be greatest among at-risk and high-risk children.