To compile curves for Body Mass Index (BMI) for Italian children and adolescents. Cross sectional study. All primary and secondary schools of Verona, Italy between October 1986 and January 1987. 20,796 males and 21,073 females children, aged 3-19 y. Weight and height were measured using Salus balances, and age in days was calculated between the date of measurement and that of birth: centiles of BMI by age were calculated by the LMS method of Cole (1990). The centiles obtained were similar to those obtained in UK by Cole et al, 1995. Compared to Cachera's data for France and Hammer's for USA, our BMI values are higher, though closer to the American than the French ones.