Research Findings: In this article, we review research on the relations of self-regulation and its dispositional substrate, effortful control, to variables involved in school success. First, we present a conceptual model in which the relation between self-regulation/effortful control and academic performance is mediated by low maladjustment and high-quality relationships with peers and teachers, as well as school engagement. Then we review research indicating that effortful control and related skills are indeed related to maladjustment, social skills, relationships with teachers and peers, school engagement, as well as academic performance. Practice or Policy: Initial findings are consistent with the view that self-regulatory capacities involved in effortful control are associated with the aforementioned variables; only limited evidence of mediated relations is currently available. (Contains 1 table and 1 figure.)