OBJECTIVE To study the influences of parental alcohol problems on adolescents' alcohol consumption and motivations to drink alcohol. METHODS A community sample of 1744 adolescents from schools in South Wales completed the 6-item Children of Alcoholics Screening Test, Drinking Motives Questionnaire, and survey measures of alcohol consumption. RESULTS Children of parents with alcohol problems constituted almost one-fifth of the sample group and were found to drink more frequently, more heavily, and more often alone than children of parents without alcohol problems. Parental alcohol problems were also related to internal motives to drink (e.g. coping) in their adolescent children. Across the entire sample, internal motives to drink interacted with parental alcohol problems in predicting alcohol consumption and drinking frequency. CONCLUSIONS Parental alcohol problems appeared to co-exist with an asocial pattern of alcohol consumption in adolescents that involves drinking alone and drinking to feel intoxicated or to forget about problems. In addition to the external, social motives to drink, which are shared by most adolescents, nearly one in five of the adolescents studied reported salient internal motives to drink that tended to coexist with alcohol problems in their parents.