Background This study explored ethnic inequalities in dental caries among adults and assessed the role of socioeconomic position (SEP) in explaining those inequalities. Methods We analysed data on 2013 adults aged 16-65 years, from the East London Oral Health Inequality (ELOHI) Study, which included a random sample of adults and children living in East London in 2009-10. Participants completed a questionnaire and were clinically examined for dental caries at home. Dental caries was measured using the number of decayed, missing and filled teeth or DMFT index. Ethnic inequalities in dental caries were assessed in negative binomial regression models before and after adjustment for demographic (sex and age groups) and SEP measures (education and socioeconomic classification). Results White Eastern European and White Other had higher DMFT, whereas all Asian (Pakistani, Indian, Bangladeshi and Other) and all Black (African, Caribbean and Other) ethnic groups had lower DMFT than White British. Similar inequalities were found for the number of filled and missing teeth, but there were no differences in the number of decayed teeth between ethnic groups. Conclusions This study showed considerable disparities in dental caries between and within the major ethnic categories, which were independent of demographics and SEP.