The Good Behavior Game (GBG, Barrish, Saunders, & Wolf, 1969) and the PATHS Curriculum (Promoting Alternative Thinking Strategies; Greenberg, Kusche, Cook, & Quamma, 1995) represent 2 universal, elementary school, preventive interventions which have been shown in large-scale, randomized controlled trials to have an immediate and beneficial impact (GBG, Dolan et al., 1993; PATHS, Conduct Problems Prevention Research Group [CPPRG], 1999) on aggressive/disruptive and off-task behavior. Importantly, both risk behaviors are strong predictors of antisocial behavior, drug abuse, and low educational and occupational attainment in adolescence and young adulthood (Kellam et al., 2008). What has yet to be explored within a randomized controlled trial is whether the combination of these interventions would yield significantly greater impact on aggressive/disruptive and off-task behavior than the GBG alone. One reason for expecting additive if not synergistic effects as a result of combining the two interventions is that the GBG, by increasing attention to task and reducing disruptive behavior in the classroom, may facilitate the acquisition of the emotion regulation, social problem-solving, and conflict resolution skills taught in PATHS. To that end, a group randomized, effectiveness trial was carried out, wherein 27 schools were randomly assigned to one of 3 conditions, (a) the PAX GBG Alone (Embry, Staatemeier, Richardson, Lauger, & Mitich, 2003), (b) PATHS to PAX (that is, the PAX GBG + PATHS), or (c) a standard setting (control) condition. Classroom observations and teacher ratings of student behavior were carried out at pretest and 6 months later at posttest. Limited evidence of the superiority of the combined approach was found and potential reasons why and future directions are discussed. (PsycINFO Database Record (c) 2019 APA, all rights reserved).