Early alcohol drinking has been hypothesized to cause alcohol-related problems in adulthood. In addition, a potential role for genetic factors exist in the etiology of some types of alcoholism. The objective of the present study was to determine if taste aversion training to ethanol during adolescence in previously ethanol-naive, alcohol-preferring P and high-alcohol drinking HAD-1 lines of rats would retard or prevent the onset of high alcohol drinking. Taste aversion training began at 30 days of age. Male and female rat pups were fluid deprived for 24 hr before 30 min access to a 10% [v/v] ethanol solution, followed by an intraperitoneal injection of either saline or 0.15 M LiCl (10 ml/kg). A total of five training sessions were administered every other day with unrestricted access to water on intervening training days. Twenty-four hours after the last training trial, rats were given continuous free-choice between water and 10% ethanol for 4 weeks with food available and libitum. There were no obvious gender or line differences to the effects of taste aversion training. All LiCl-treated subjects avoided the usually preferred ethanol solution for the entire 4-week test period, whereas saline-treated rats steadily increased their alcohol intake to over 6.0 g/kg/day by week 4. Rats in the saline and LiCl-treated groups gained weight at comparable rates, and the groups did not differ in total fluid intake. The findings demonstrate that early environmental intervention can prevent the onset of high alcohol drinking in the selectively bred alcohol-preferring P and high-alcohol drinking HAD-1 lines of rats.