Objective: To assess the interrelationship between ethnicity, migration status and dental caries experience among adults in East London. Methods: We analysed data from 1910 adults (16-65 years) representing 9 ethnic groups, who took part in a community-based health survey in East London. Participants completed a supervised questionnaire and were clinically examined by trained dentists. Dental caries was assessed with the number of decayed, missing and filled teeth (DMFT). The association of ethnicity, nativity status and migration history with DMFT was assessed in negative binomial regression models controlling for demographic, socioeconomic and behavioural factors. Results: White migrants had greater DMFT than UK-born adults, whereas every Asian and Black migrant group had lower DMFT than adults of the same ethnic group born in the UK (albeit significant only for Black Caribbean and Asian Others). Among foreign-born adults, age at arrival (Rate Ratio: 1.03; 95% Confidence Interval: 1.01-1.05) and length of residence (1.04; 95% CI: 1.02-1.06) were positively associated with DMFT. A significant interaction between both factors was also found, with more pronounced differences between older and younger migrants at longer stay in the UK for White Others, Black Caribbean and Asian Others. Conclusion: Large inequalities in caries experience were found between foreign- and UK-born adults, with considerable variation across ethnic groups. Looking beyond cultural explanations, in favour of social and environmental factors, may help to explain those inequalities.