The effect of human growth hormone (6IU/m2 twice weekly i.m.) on standing, sitting, and subischial leg height, on arm length, head circumference, fronto-occipital and biparietal head diameter, bi-iliac (pelvis) and bihumeral (shoulder) width, body weight, triceps and subscapular skinfold thickness, and upper arm and calf circumferences was studied longitudinally over a period of 2 years in 37 prepubertal growth hormone deficient patients (29 boys, 8 girls). Thirteen of them had isolated growth hormone deficiency, 18 combined defects with other anterior pituitary hormone deficiencies, and 6 had been operated for a craniopharyngioma. The most retarded height and length measurements were influenced most markedly by treatment in the fashion of a characteristic catch-up growth, while head circumference, which was less retarded initially, increased more slowly. With exception of craniopharyngioma patients, who became slightly eunuchoid, both proportions (sitting height versus subischial leg height) were not changed by treatment. The disproportions of shoulder and hip width (relatively wide pelvis, narrow shoulders before treatment) tended to be normalized. The results in patients with operated craniopharyngioma were not as good as in those with idiopathic growth hormone deficiency.