This study examined rates, correlates and an interpersonal model of nonsuicidal self-injury (NSSI) among a sample of 508 sixth, seventh, and eighth graders. Questionnaires assessing NSSI, related health-risk behaviors, and relationships with parents were administered two times over an 11-month period. Overall, 7.5% reported engaging in NSSI within the past year with no significant differences across genders, ethnicities, or grade. Those engaging in NSSI were more likely to report having smoked cigarettes, taken drugs, and engaged in maladaptive eating behaviors. Consistent with an interpersonal model, those engaging in NSSI reported significant increases in the quality of their relationships with fathers over time. Clinical implications include considering the role of family members in efforts to prevent and treat NSSI. (Contains 3 tables and 1 figure.)