INTRODUCTION: the analysis of the temporal distribution of events in the health-disease process is one of the strategies of the oldest and most valuable research in epidemiology and public health. OBJECTIVE: To analyze changes in the anthropometric profile of preschool children that frequented public day-care centers of Taubate, Brazil. METHOD: 755 children in 1997 and 1448 in 2007 were evaluated. The study variables were: age, sex, weight, stature and body mass index (BMI). The transformation of the anthropometric values in Z scores was carried through the reference data of the CDC/NCHS (2000). The comparisons between the two moments were made by χ-squared and t-Student tests (α = 0,05). RESULTS: positive secular trend of growth was observed between 1997 and 2007 with a significant increase in the average values of Z scores of stature in both sexes, boys: 0,04 to 0,39 and girls: 0,05 to 0,33, and of weight, boys; -0,03 to 0,26 and girls: 0,03 to 0,21. The averages of BMI showed no significant difference (boys 0,02 to 0,07 and girls 0,09 to 0,12). There was an increase of thinness prevalence, 9,8 to 12,6% children, and also of weight excess, 17,0 to 20,9%, between 1997 and 2007. CONCLUSIONS: Preschool children from the city of Taubaté showed a quite significant increase in the growth trend between 1997 and 2007, more height than weight, which was accompanied by an increased prevalence of thin children and especially overweight. This indicates that possibly the improvement of the population, and impact positively on growth in stature of preschool children, can also result in the installation of an early and intense nutritional transition process, even outside the major metropolitan areas.