GH, 0.1 IU/kg/day 6 days/week, was given to 30 early pubertal short patients for 3 years. There were 16 males, aged 14.4 +/- 0.8 years, and 14 females, aged 12.2 +/- 1.2 years, at pubertal stage 2 or 3 with slow growth (4.2 +/- 1.2 cm/year) and no detected GH insufficiency or other cause for short stature. They were randomized in 2 groups: group A with GH alone, and group B with GH and a gonadotropin-releasing hormone agonist during the first 2 years. 28 of the 30 patients completed 3 years of treatment. The annual growth rate increased during the 1st year in both groups and sexes, the increase being significant (p < 0.01) in group A only. Patients of group A kept an improved growth velocity in the 2nd year, then returned to pretreatment growth rate in the 3rd year, while completing their sexual development and bone maturation. Their height, expressed as standard deviation score (SDS) for bone age, improved in the first 2 years, but decreased thereafter. Group B patients returned to pretreatment growth velocity in the 2nd year, and had no significant improvement in growth rate in the 3rd year with GH alone. Their bone maturation, slow when on the GnRH agonist, accelerated when sexual development resumed. At the end of the 3 years, height, expressed as SDS for age, improved in group A from -2.5 +/- 0.6 to -1.5 +/- 0.4 in males (p < 0.05) and from -2.8 +/- 0.5 to -2.1 +/- 0.9 in females (NS).(ABSTRACT TRUNCATED AT 250 WORDS)