This study of the etiology of drug use explores the influence of family relationship variables (parental support) on selfidentification, and alcohol and marijuana use of 258 inner-city, male adolescents. A latent variable structural model of the effect of parental support on alcohol and drug use, mediated by self-identification, was estimated using a maximum likelihood solution. Results support the adequacy of the model. Perceived family support and self-identification were significantly related to reported alcohol and marijuana use. In addition, alcohol consumption functions as a mediator variable and affects the relationship for both perceived family support and selfidentification with marijuana use. Ethnic background, Black versus Puerto Rican, did not have a direct effect on these variables. Finally, the model suggests a direct relationship between youths 1 use of alcohol and marijuana. It was hypothesized that this relationship is a product of environmental and socio-cultural contexts wherein a variety of illicit drug-taking is available, encouraged, and rewarded. The discussion examines the implications of the results for the influence of perceived family suppost and the quality of youth-family relationships for researchers. The role of alcohol use as a mediating variable is also discussed.We are grateful for the assistance given to us by the principal, teachers and parents of the junior high school who must remain anonymous. The reactions of many youngsters to earlier versions of the survey instruments were valuable to our research effort. The support and encouragement of the New York State Office of Drug Abuse Services, and especially Douglas S. Lipton,