We investigated whether preschoolers' social-emotional competencies predict their peer relationships and academic achievements during grade one. Measures of cool and hot executive functions, theory of mind, social-problem-solving, and peer acceptance were administered to a sample of 48 preschoolers (M = 77.91 months). Academic achievement and peer acceptance were assessed at the end of Grade 1. A path analysis revealed that cool and hot executive functioning during preschool had a direct impact on academic achievement in elementary school and an indirect effect on peer acceptance via the theory of mind and social-problem-solving, respectively. Further, peer acceptance in preschool had a positive direct effect on peer acceptance during grade one. These findings indicate the vital role of social-emotional competencies on peer relationships and academic achievement. Future study should include additional measures to examine the effect of preschooler's cool and hot executive functions on later school adjustment.