The relative impact of biological family history of alcoholism and exposure to abusive parental drinking on alcohol effect expectancies of adolescent offspring were investigated in the present study. Exposure to familial models of alcohol abuse and biological family history were both predictive of positive alcohol effect expectancies of adolescent offspring. Degree of exposure to an alcohol-abusing family member mediated the relationship between biological family history of alcoholism and adolescent alcohol outcome expectancies. These results support prior findings of expectancy differences between youths with and without a family background of alcoholism and provide evidence supporting the significance of family modeling influences in the development of adolescents' alcohol expectancies.