Bonding to school has been shown to be a protective factor against many problem behaviors. This study examines the effects of intervention during the elementary grades on changes in school bonding from middle school through high school, using hierarchical linear modeling. A full intervention group (Grades 1-6), a late intervention group (interventions in Grades 5 and 6 only), and a control group offered no special intervention were compared. The full intervention group was significantly more bonded to school than the control group at ages 13 and 18. Moreover, the full intervention group showed a curvilinear change in school bonding over time, decreasing to age 16 and then increasing to age 18, whereas bonding to school in both the control and late intervention groups continued to decline from age 13 to age 18. These findings suggest that social development interventions through elementary school can have positive long-term effects on school bonding and demonstrate the importance of long-term follow-up studies of preventive interventions.