Recent reports have indicated that the use of alcohol is related to sexual behavior (such as unprotected intercourse) that is high-risk for HIV infection. However, most of these studies have collected data from convenience samples, using measures of varying specificity. This paper describes a study designed to investigate the relationship of alcohol use to unsafe sexual activity in a representative sample of adults. Data were collected from 2058 respondents as part of a survey of a multi-stage area probability sample of the adult household population of the 48 contiguous United States. The interview instrument included measures of alcohol use, sexual activity and condom use. Logistic regression analyses showed that heavier drinkers were more likely to be sexually active, and if sexually active, were more likely to have had more than one sexual partner in the previous year. However, drinking variables were in general not significantly related to condom use. These results suggest that alcohol use may be more strongly related to lifestyle variables (general sexual activity and number of sexual partners) than to more concrete behavioral variables such as condom use. Because these data are correlational, the findings are also consistent with the notion of a general constellation of risk-taking or sensation-seeking activities that includes alcohol use and sexual activity.