In order to investigate the value of growth hormone (GH) treatment during late puberty, we studied the effect of human GH (hGH) administration (0.85 +/- 0.30 IU/kg/week; range: 0.44-1.28) on height velocity (HV) after the peak of the pubertal growth spurt in a group of 10 (4 girls and 6 boys) short normal children (GH peak after pharmacological stimulation: 15.5 +/- 2.3 ng/ml) with growth retardation (height: 2.6 +/- 0.3 SD) and puberty Tanner stage 4. A group of 10 untreated children, observed prior to the study, served as controls. The children were regularly measured during their pubertal growth spurt, and HV (cm/year) was calculated every 6 months. The pretreatment evaluation consisted of 2 consecutive 6-month periods characterized by a decrease in HV of at least 25%. In the group of selected children, hGH administration was then initiated and growth variables were evaluated after 6 and 12 months of therapy. Skeletal maturation was evaluated at the beginning as well as after 6 months and 12 months of hGH therapy. In the controls, HV (mean +/- SD) had decreased from 8.8 +/- 1.8 to 4.9 +/- 1.4 cm/year during the pretreatment period (in girls from 7.9 +/- 1.4 to 4.1 +/- 0.6 cm/year and in boys from 9.6 +/- 1.6 to 5.8 +/- 1.2 cm/year). During the following semester, HV was 3.3 +/- 0.8 cm/year (girls: 3.4 +/- 1.0 and boys: 3.2 +/- 0.2 cm/year).(ABSTRACT TRUNCATED AT 250 WORDS)