This study investigates the unique contribution of microsocial and global measures of parent–child positive coregulation (PCR) in predicting children’s behavioral and social adjustment in school. Using a community sample of 102 children, ages 4–6, and their parents, we conducted nested path analytic models to identify the unique effects of 2 measures of PCR on school outcomes. Microsocial PCR independently predicted fewer externalizing and inattention/impulsive behaviors in school. Global PCR did not uniquely relate to children’s behavioral and social adjustment outcomes. Household socioeconomic status was related to both microsocial and global measures of PCR, but not directly associated with school outcomes. Findings illustrate the importance of using dynamic measures of PCR based on microsocial coding to further understand how the quality of parent–child interaction is related to children’s self-regulatory and social development during school transition.