This study explored the relationship between different indicators of acculturation and children’s caries experience. Data from 313 children attending the Dental Clinic of the European University of Madrid were analysed. Acculturation was measured via generational status, age at arrival, length of residence and language spoken at home. The association between each indicator of acculturation and caries experience was assessed in Poisson regression models adjusting for confounders. First- and second-generation migrant children had greater caries experience than Spanish-born children. These differences only persisted for first-generation migrant children after adjustment for confounders. Children who arrived in Spain before age 6 years, who lived in Spain for 10 or more years and who spoke a language other than Spanish at home had greater caries experience than Spanish-born children. Inequalities in caries experience between migrant and native children were evident (favouring the local children) and independent of family’s socioeconomic circumstances.