Child Health Services plays an important role in identifying at-risk children and intervening early to break negative trends in child health. Sociodemographic risk factors can impact the workload of Child Health Services and affect the possibilities of providing the national child healthcare programme. This study aims to present the sociodemographic characteristics of families who are registered within the Child Health Services, as defined by the Child adjusted Care Need Index. By collecting personal identification numbers from children six years or younger registered at a child healthcare centre, and combining this with their caregiver's sociodemographic background, this study was able to create a sociodemographic index for each child healthcare centre in Sweden. The study included 687,543 children and 1,335,540 caregivers from 981 child healthcare centres in Sweden. Approximately 21% of all children in the study population had a caregiver born in Southern or Eastern Europe outside the European Union, or in Africa, Asia, or South America, 7% had single parents, 17% had at least one unemployed caregiver, and 9% had at least one caregiver who had not completed high school. The average input values and the average index values varied widely both between and within the regions. This study displays a large variation in sociodemographics for child healthcare centres both within and between regions. Since several regions and national agencies in Sweden use the Child adjusted Care Need Index, it is necessary to keep the dispersion in mind.