The aim of the present study was to suggest a causal model of dental caries and to discuss some quantitative interpretations of this model. Three age groups of children (4, 8 and 13 yr) from three different areas in Sweden were included. The caries status of the children was examined. A 7-day record (4-and 8-yr-olds) and a dietary history (13-yr-olds) were used to estimate food intake. Sociodemographic data and data of caries preventive measures were obtained from parents/children. A causal model of dental caries is suggested and some quantitative interpretations are made by means of path analyses. Hypothetical examples of results of changes in caries determinants are given.