Abstract Background More information on the health-related repercussions of age at onset of adolescent drinking is needed. The aim of this study was to examine the associations between self-reported age at first drink and age at first alcohol intoxication with the risk of death by age 30. Methods The sample (n = 6564; 49.1% males) included all participants of the Northern Finland Birth Cohort Study 1986 (NFBC1986) for whom the two measures of adolescent drinking were available. Self-reported age at onset of first drink and first alcohol intoxication were analyzed along with background variables and data regarding subsequent psychiatric diagnoses. Adolescents were dichotomized into those reporting age at first drink and age at first intoxication before or after age 14. Cox regression was used to calculate hazard ratios (HRs) with 95% confidence interval (95% CI) for death by age 30. Results By the age of 30, 0.7% (n = 47) of all 6564 participants were deceased. In the multivariable models, male gender and a history of illicit substance use in adolescence were associated with both all-cause mortality and mortality due to accidents or suicide. After controlling for confounding variables, age at first alcohol intoxication was associated with all-cause mortality (HR 2.33; 95% CI 1.04–5.20) as well as death due to accidents or suicide (HR 2.99; 95% CI 1.11–8.05). Conclusions Earlier age at first intoxication carries long-term repercussions with respect to premature loss of life. Efforts should be made targeting the prolongation of initiating binge drinking in adolescence to diminish this mortality risk.