Values of the waist-hip ratio (WHR), expressed as percentiles and stratified by sex and age, were obtained from a simple judgment sample of 7285 schoolchildren and adolescents (3721 males and 3564 females) aged between 4.5 and 20.5 years. WHR is higher with age in males, and it changes more gradually chronologically also. The graph for males shows three relative maxima at 6, 11-12 and 15-16 years; and for females, two relative maxima at 10 and 13 years. In females, there are two sharp reductions between 10 and 13 and between 13 and 16 years of age. The changes in WHR are associated with age and sexual maturation in both sexes. We conclude that WHR might be useful in assessing body fat distribution in late childhood and adolescence.