This meta-analysis examined which classroom management strategies and programs enhanced students' academic, behavioral, social-emotional, and motivational outcomes in primary education. The analysis included 54 random and nonrandom controlled intervention studies published in the past decade (2003-2013). Results showed small but significant effects (average g = 0.22) on all outcomes, except for motivational outcomes. Programs were coded for the presence/absence of four categories of strategies: focusing on the teacher, on student behavior, on students' social-emotional development, and on teacher-student relationships. Focusing on the students' social-emotional development appeared to have the largest contribution to the interventions' effectiveness, in particular on the social-emotional outcomes. Moreover, we found a tentative result that students' academic outcomes benefitted from teacher-focused programs.