The contributions of genetic and both positive and negative environmental factors were tested in the prediction of alcohol abuse/dependence among 300 adult adoptees. No direct effects for either genetic or environmental factors were significant in the prediction of adoptee alcohol abuse/dependence. However, among women, early-life family conflict and psychopathology in the adoptive family interacted with a biological background of alcoholism. Among women with at least one alcoholic biological parent, conflict or psychopathology in the adoptive family increased the probability of alcohol abuse and/or dependence. Among men, no significant interactions were found between a biological background of alcoholism and environmental variables. Results suggest a pattern of gene-environment interaction among women.