This study examined the way children's engagement with teachers, peers, and tasks in the preschool classroom was related to their gains in self-regulation skills. Children's positive engagement with their teachers was related to increases in their compliance and cognitive control. Children's active and sustained engagement with classroom activities was linked with gains in their emotion management. The combination of children's positive and prosocial engagement with teachers or peers and high task engagement or low negative classroom engagement was linked with greater gains in self-regulation. (author abstract)