The authors recruited college students (N = 648) and investigated relationships among academic and social self-efficacy, relational aggression from parents and peers, and nonsuicidal self-injury (NSSI). Results indicated that both types of self-efficacy were related inversely to NSSI. Academic self-efficacy mediated the relationship between parental emotional abuse and NSSI, whereas social self-efficacy mediated the relationship between peer victimization and NSSI. Clinical implications of these findings for college counselors are discussed.