Parents (n=388) were found to be a major source of supply of alcoholic beverages to their underage adolescents. Of the 70 percent of parents who believed that their adolescents were currently consuming alcoholic beverages, 37 percent reported supplying them with more than a sip of alcohol in the last 3 months. This finding was significantly associated with parents' perception that their adolescent child was already drinking alcoholic beverages. Parents' supplying alcoholic beverages to their children was also linked to parental monitoring of the child, suggesting that parents who knew their child was consuming alcoholic beverages outside the home felt more comfortable having the adolescent consume them in the home under parental supervision. Parents' supplying alcoholic beverages to an adolescent child was not associated with the socioeconomic characteristics of the parent or child, nor was it related to parents' drinking patterns. The authors advise that parents supplying alcoholic beverages to their children may be contributing to the normalization of earlier initiation to and use of alcoholic beverages by the current generation of adolescents. Australian students report that when parents supply them with alcoholic beverages while at home, they drink less than when outside the home; however, parental supplying of alcohol to underage children has been linked to increased alcohol use over time; and any protective effects of parental monitoring disappear when there is "binge" drinking. The study surveyed the convenience sample of 388 parents about their beliefs regarding the use of and age of initiation to alcohol by adolescents, parental supply of alcohol to underage adolescent children, parental monitoring of their children, parents' alcohol consumption, and sociodemographic characteristics. 2 tables and 32 references