Researchers have demonstrated that cognitive-behavioral intervention strategies--such as social problem solving--provided in school settings can help ameliorate the developmental risk for emotional and behavioral difficulties. In this study, we report the results of a randomized controlled trial of Tools for Getting Along (TFGA), a social problem-solving universally delivered curriculum designed to reduce the developmental risk for serious emotional or behavioral problems among upper elementary grade students. We analyzed pre-intervention and post-intervention teacher-report and student self-report data from 14 schools, 87 classrooms, and a total of 1296 students using multilevel modeling. Results (effect sizes calculated using Hedges' g) indicated that students who were taught TFGA had a more positive approach to problem solving (g = 0.11) and a more rational problem-solving style (g = 0.16). Treated students with relatively poor baseline scores benefited from TFGA on (a) problem-solving knowledge (g = 1.54); (b) teacher-rated executive functioning (g = 0.35 for Behavior Regulation and 0.32 for Metacognition), and proactive aggression (g = 0.20); and (c) self-reported trait anger (g = 0.17) and anger expression (g = 0.21). Thus, TFGA may reduce risk for emotional and behavioral difficulties by improving students' cognitive and emotional self-regulation and increasing their pro-social choices. (Contains 4 tables.)