A total of 203 patients with Turner's syndrome were treated with three different kinds of recombinant hGH preparations for one year. One hundred and seven patients were treated with hGH at a weekly dosage of 0.5 IU/kg, 71 with 1.0 IU.kg-1.week-1, and the remaining 25 patients with combined administration of 0.5 IU.kg-1.week-1 hGH and a small amount of anabolic steroid. All three treatment groups showed statistically significant growth increases during the treatment. Fifty percent of the patients treated with 0.5 IU.kg-1.week-1 and 80% of the patients treated with 1.0 IU.kg-1.week-1 showed growth rates more than 2 cm per year greater than pretreatment values or beyond the second SD of the untreated growth rate. Plasma somatomedin C levels were elevated and no remarkable advances in bone age were observed during the treatment. Antibody against hGH was observed in 71.4% and 10.8% of the methionyl-hGH and methionine-free-hGH treated patients, respectively. However, the antibodies did not suppress the growth promoting effect of methionyl-hGH. Otherwise, there were no significant changes in physical or laboratory examinations. No glucose intolerance was observed. These results indicate that hGH treatment is useful for the acceleration of growth velocity in patients with Turner's syndrome.