Our understanding of the adverse effects of early child physical and sexual abuse has developed to a point where there is need to elucidate the processes by which various developmental outcomes occur. Limited variability on key measures of family stress and in youths' drug use, other delinquent behavior and abuse histories in the general population has limited theory development. Using data from an ongoing, longitudinal study of juvenile detainees, we test a developmental damage model of the relationships among the youths' family background and problem factors, their sexual victimization and physical abuse experiences, and their substance use and delinquent behavior over time. The hypothesized model was supported by the data. Theoretical and policy implications of the results are drawn. In particular, early intervention with high-risk youths and their families is needed to address effectively their problems and troubled behavior before drug use and delinquent careers become firmly established.