Unlike most studies on the topic, the study focused on a sample of delinquent youth who resided in the Philadelphia metropolitan area. The study aim was to develop knowledge that could be translated into recommendations for program design within a juvenile justice system. The study sample included 7,806 delinquency cases committed by Philadelphia's Family Court to any program between 1994 and 1996 and excluded only youth who were committed to ordinary probation. Because self-report data were missing on a large proportion of the sample, only 3,980 delinquency cases were analyzed. Drug abuse levels by black youth were substantially lower than those of white and Hispanic youth. Risk factors were more powerful than protective factors in predicting drug abuse among delinquent youth. Among delinquent youth, school commitment was the strongest protective factor, followed by intimacy and communication for the low school commitment group and self-esteem for youth whose school commitment scores were high. Of potential risk factors, father's drug abuse, mother's alcohol abuse, history of family violence, and prior referral for abuse or neglect were the strongest predictors of drug abuse. Racial differences existed in the manner in which protective and risk factors were associated with juvenile drug abuse. Implications of the findings for further research are discussed. 40 references, 10 notes, 3 tables, and 5 figures