The aim of the present study was to explore the possibility of predicting the incidence of dental caries from obesity. The subjects were 516 children living in Luvia, Finland, born between 1972 and 1981. Obesity alone was not a very good predictor of dental decay. When predicting caries in the permanent first molars using both earlier obesity and earlier caries experience as predicting indicators, 65-70% of the true risk group was identified. This combination was even better for the prediction of caries in permanent second molars.