Using a representative sample of low-income, primarily minority adolescents (N=647, aged 10-14 years at Wave 1), this study examined bidirectional longitudinal relations between nonresident father involvement, defined as contact and responsibility for children's care and behavior, and adolescent engagement in delinquent activities. Autoregressive and fixed effects models found that higher nonresident father involvement predicted subsequent decreases in adolescent delinquency, particularly for youth with initial engagement in delinquent activities. Adolescent delinquency did not predict subsequent changes in father involvement. However, the two factors covaried: As adolescent delinquency increased, so too did father involvement, suggesting that nonresident fathers may increase their involvement in the face of adolescent problem behavior, with this pattern driven primarily by African American families.