BACKGROUNDDental caries and obesity are multifactorial diseases with diet being a common contributory factor.OBJECTIVEThe main purpose of the present study was to investigate the association between dental caries and obesity among special care female school children in Makkah City, Saudi Arabia.DESIGNAnalytical cross-sectional study.SETTINGSpecial schools in Makkah City.STUDY POPULATION AND METHODSSchools were chosen by lottery and female children were randomly selected. Dental caries detection was performed according to the World Health Organization criteria. The medical evaluation assessed the body mass index (BMI).MAIN OUTCOME MEASURESWith appropriate sample weighting, relationships between dmft/DMFT (decayed, missing, filled teeth for deciduous and permanent dentition) and obesity were assessed using multilevel logistic regression.RESULTSIn 275 special care children, the prevalence of dental caries was 56.7 percent. The mean dmft and DMFT scores for the entire study population were 3.9 (4.8) and 3.2 (4.1), respectively. Forty percent of children were mentally retarded, 22.2% presented with deafness, blindness or both, 18.9% presented with Down syndrome and 14.9% were autistic. From the total sample, the mean BMI was 20.2 (2.8). When adjusted for covariates, the logistic regression model showed strong association between caries and obesity (adjusted odds ratio=2.9; 95% CI=1.2–4.9).CONCLUSIONThis study demonstrated a significant association between caries frequency and overweight/ obesity in special care school children.LIMITATIONSSince the data was cross-sectional, causal relationships cannot be established and the observed association could be due to other unexplored factors. Because of cultural and ethical consideration, including segregation of gender in Saudi Arabia, only female children were included in the present study, which limited the findings.