As the 21st century begins, most programs in early care and education have not yet integrated peacebuilding strategies into their preschool settings. A growing body of literature on social emotional learning points to the advantages of early exposure. This study shows the key role of the teacher in facilitating conflict resolution in preschool classrooms. Findings demonstrate an expanded understanding of conflict and improved use of conflict resolution strategies when teachers are trained and learn about their own attitudes and preferences as conflict managers. The I Can Problem Solve program proves to be a very good fit for preschool programs that want an inexpensive, evidence-based curriculum that helps teachers guide young children to resolve their own interpersonal conflicts.