The present paper compared drinking and drug use in Adult Children of Alcoholics (ACOAs), compared to non-ACOAs, among college students. Participants were 572 undergraduates. ACOAs were more likely to be current drug users than non-ACOAs. ACOAs reported initiating alcohol use earlier than non-ACOAs; however, ACOAs did not drink more often or more heavily than non-ACOAs. Among ACOAs, suspecting one's mother or both parents of alcohol abuse predicted greater likelihood of lifetime drinking; suspecting one's father of alcohol abuse was associated with more frequent drinking during the school year. The fact that ACOA status was not associated with the frequency and amount of alcohol consumed may reflect that 73.3% of the sample were drinkers, and 31.9% met criteria for binge drinking in the previous month.