Objective: This study explored whether college students who were first intoxicated by alcohol at ages younger than 19 are more likely to become alcohol dependent and frequent heavy drinkers, drive after drinking, ride with intoxicated drivers and be injured after drinking. It also investigated whether these results occur because these students believe they can drink more and still drive legally and safely. Method: In 1999, 14,138 of 23,751 full-time 4-year students from a random sample of 119 college and universities nationwide completed self-administered questionnaires (response rate: 60%). This analysis focused on 12,550 who were aged 19 or older. Respondents were asked the age at which they first got drunk, as well as questions about recent alcohol-related behaviors and consequences. Results: Compared with respondents first drunk at age 19 or older, those first drunk prior to age 19 were significantly more likely to be alcohol dependent and frequent heavy drinkers, to report driving after any drinking,...