OBJECTIVE: To examine the association between use of alcohol and cigarettes among adolescents and their early socioeconomic background. METHODS: Members of a longitudinal birth cohort (Avon Longitudinal Study of Parents and Children [ALSPAC], United Kingdom) were invited to attend a personal interview. A total of 5837 children aged 13 years were asked about previous consumption of alcohol and tobacco. Information on parental socioeconomic position, collected from questionnaires from the mother, included both social class and education of the expectant mother and her partner and average household disposable income in early preschool childhood. The impact of missing data was assessed by multiple imputation. RESULTS: Consuming a drink of alcohol in the previous 6 months was linearly associated with higher income levels even when adjusting for other socioeconomic indicators. In contrast, both the risk of binge drinking and recent drinking was lower for children whose mothers had a higher educational level. Smoking tobacco was associated with lower socioeconomic position irrespective of the indicator used. Analyses after imputation of missing data confirmed these associations. CONCLUSIONS: Alcohol drinking was more common in young people from higher-income households but less common with higher levels of maternal education. A consistent inverse socioeconomic gradient with tobacco smoking was apparent. These results may reflect how different aspects of socioeconomic position can influence health behavior in opposing directions. Higher income may increase the availability of alcohol in the family, whereas mothers with higher educational attainment might encourage more healthy behaviors in their children, including reduced alcohol use.