Various research studies have suggested that an external locus of control regarding drinking-related behavior inhibits recovery from alcoholism. The relative influence of alcoholism and parental alcoholism upon drinking-related locus of control was the focus of the present study. Subjects who were both alcoholics and the adult children of alcoholics (ACOA) were found to have a much higher extenal drinking-related locus of control than persons with only one of these two conditions. Alcoholics who were not ACOA were found to have a higher level of externalily than subjects who were ACOA but not alcoholics, who, in, turn, were more external in their control orientation than subjects who were neither alcoholics nor ACOA. Of particular importance was the finding that the interaction of alcoholism and parental alcoholism was a predictor of drinking related locus of control (p = .08), suggesting that the effect of these two conditions upon externality may not be purely cumulative.