Autonomy was examined as an attitudinal construct within the Theory of Reasoned Action. Longitudinal data from 2,493 seventh grade students nested in 40 schools were analyzed using a structural equation model. Autonomy was negatively correlated with intention to use alcohol and subsequent alcohol use at a later wave, and intention to use fully mediated the effect of autonomy on subsequent alcohol use. These results are consistent with the proposition that when personal autonomy is perceived as inconsistent with alcohol use among younger adolescents, students indicate a lower intention to use alcohol and use less alcohol during the following school year. (Published Abstract)