A total of 94 patients with Turner's syndrome were treated with methionine-free recombinant hGH for one to two years. Forty-seven patients were treated with r-hGH at a weekly dosage of 0.5 IU/kg and another 47 were treated with 1.0 IU/kg/w by daily sc injection. Both treatment groups showed statistically significant growth increase during the treatment from 3.7 +/- 1.0 to 5.2 +/- 1.3 and from 3.5 +/- 0.9 to 6.3 +/- 1.4 (Mean +/- SD) cm/year, respectively, during the first year of treatment. During the 2nd year of treatment, the growth rate declined to 4.1 +/- 1.1 cm/year under 0.5 IU/kg/w treatment and to 4.6 +/- 1.1 cm/year under 1.0 IU/kg/w treatment. Nevertheless, the growth rates in the treatment groups remained significantly greater than in the untreated controls. Plasma somatomedin C increased and no remarkable increase in bone age was observed during the treatment in either treatment group. Antibody to hGH was observed in 14.8% of the patients at the end of the first year of treatment, however the incidence was decreased to 4.7% by the end of the second year of treatment. Otherwise, there were no significant changes detected in physical or laboratory tests. No glucose intolerance necessitating treatment was observed. These results indicate that hGH treatment is useful in accelerating growth in patients with Turner's syndrome.