OBJECTIVE In this study, the cross-temporal relationship between family social support and adolescent alcohol use was examined. A primary aim was to investigate the mechanisms through which family social support affects drinking among youth. Another aim was to examine reciprocal relationships among the study variables. METHODS Four-wave (with 6-month intervals) panel survey data collected from 840 middle adolescent boys (n = 443) and girls (n = 397) attending a suburban school district in western New York were analyzed using structural equation modeling with maximum likelihood estimation. RESULTS Analyses revealed that family social support was indirectly associated with decreased alcohol consumption among the respondents, primarily through variables measuring religiosity, school grades and peer alcohol use. In addition, adolescent alcohol use was directly associated with subsequent increases in peer alcohol use and later decreases in school performance. Results also showed that receiving good grades in school predicted moderate increases in family social support. CONCLUSIONS The findings of this study are discussed in terms of the interrelationships that exist among multiple socializing influences and alcohol use among adolescents.