BACKGROUND: Illicit drug use in adolescence has been linked to drug use and poor mental health in adult life, but few studies have examined the relation between adult economic and criminal justice outcomes. METHODS: We analysed data from 14 082 participants (6999 women) in the 1970 British Birth Cohort Study. Illicit drug use over study members' lifetime and in the past year were self-reported at 16 years of age. Thirteen outcomes were self-reported at 30 years of age, including illicit drug use, smoking, problems with alcohol, mental and physical health, experience of socioeconomic disadvantage and experiences with the criminal justice system. RESULTS: At 16 years of age, 20.3% of the participants had ever tried an illicit drug and 7.2% had used in the past year. After adjustment for childhood socioeconomic status and mental health problems, and following correction for multiple testing, there was a dose-response association between illicit drug use at 16 years with illicit drug use in adult life in the past year (OR; 95% CI - 1.83, 1.51 to 3.12), experiencing homelessness (1.74, 1.16 to 2.62), being arrested (1.57, 1.29 to 1.92) and cautioned (1.97, 1.50 to 2.57) by the police, and being found guilty at court (1.73, 1.34 to 2.23). CONCLUSIONS: Adolescent drug use was associated with an array of social and criminal outcomes in later life.