The objective of this study is to determine the correlation between the number of erupted primary teeth, the age, sex and the somatic measures of weight and height (length) in a Brazilian population based cross sectional study. A systematic sampling was used. Complete and consistent data were obtained from 870 of a total of 908 children from birth to 36 months of age. Statistical analysis com-prised a multiple regression equation, where the number of erupted primary teeth was modeled as the dependent variable and the initial specification included the following independent variables: age, sex, birth-length, birth-weight, weight and length measured at the examination of the child. Results showed that in this study, 86% of the variation of the number of erupted primary teeth was explained by age and height of children (p<0.001). Age and height showed a stronger correlation with the number of erupted primary teeth than all the tested variables together. It was concluded that primary teeth erup-tion is highly influenced by age and height (length) of the child. Using the best regression equation found, a chart was constructed where the variation of the number of erupted primary teeth is given according to age and height of the child.