To investigate the effect of diabetes on the growth of children and to detect possible impairment of their final height, 58 Chinese subjects (22 boys; 36 girls) with childhood diabetes were studied longitudinally from diagnosis. Mean onset age at presentation was 8. 70 years. All patients were measured and weighed at diagnosis and every 3-4 months during the follow up period. Their height and weight measurements were converted to standard deviation scores (S.D. S.) using normal height and weight-for-height reference standards for Chinese children established in Hong Kong. The mean height S.D.S. for boys and girls at diagnosis were +0.76 and -0.07 (P=0.015). The mean final height S.D.S. for boys and girls were +0.14 and -0.57. The final heights of girls were significantly shorter than their target heights. At attainment of final height for diabetic girls, their mean weight-for-height S.D.S. was +0.76 indicating that they tended to become overweight. This study demonstrates the sex differences in the growth of diabetic children. Diabetic boys were tall for age at presentation but they achieved average final heights while diabetic girls attained below average adult stature and they tended to become obese.