The aim of this study was to investigate if the type of class setting is related to the utilisation of disability-related services and child welfare services outside school over time among children with mild intellectual disability (ID). A quantitative study with a longitudinal and comparative design was carried out including data from archival records concerning service utilisation among 405 children. Children in special classes were more likely than children integrated into regular classes to utilise disability-related services. Integrated children who changed school setting from regular classes to special classes were more likely to begin to utilise such services and to increase the number of services utilised, compared to children who remained integrated. Professionals in social services and schools may need to improve their collaboration around families of children with mild ID when assessing needs and providing services. Special attention may need to be devoted to children integrated into regular classes.