A sample of 103 Swedish boys and 80 Swedish girls followed longitudinally were grouped into early, average and late maturers on the basis of age at peak height velocity. In girls there were significant differences in height between the maturity groups from 5 to 14 years of age, but the final height did not differ between the groups. In boys there were significant differences in height between the maturity groups from 12 to 16 years, no significant difference at the age of 17 years, and from 18 years of age and on, late-maturing boys were significantly taller than the early maturity boys. From 21 years and onwards they were also taller than the average-maturing boys. Thus final height differed significantly between the late-maturing boys and the other two maturity groups of boys, averaging 6.5 cm and 4.2 cm, respectively.