Secular growth changes of Stockholm schoolchildren born in 1933, 1943, 1953 and 1963 were studied through samples of about 2500 children in each year. Heights and weights at the ages 7, 10 and 13 years were obtained from school health records stored in the Stockholm city archives. The increase in height and weight at these ages was more marked between the children born in 1933 and 1943 than later, except for the girls aged 7, who had no increase in height. The increase in height between the later samples was at age 7 years practically none, at age 10 years about 1 cm/decade and at age 13 years 1-2 cm/decade. The body mass index (BMI) indicated a continuous trend towards a slimmer body build for Stockholm schoolchildren at the age of 7 years. At the ages of 10 and 13 years the BMI remained fairly stable for the cohorts born from 1943 to 1963.