In this French study with recombinant somatropin, the stimulation of growth in 32 prepubertal (age 10.0 +/- 3.5 years; mean +/- SD) and 19 pubertal (age 14 +/- 1.5 years) GH deficient children was compared; the stimulation of growth was similarly good in the two groups. The height velocity SD scores increased from -2.5 +/- 1.7 and -0.9 +/- 1.5 to 2.2 +/- 1.9 and 1.6 +/- 1.6 in prepubertal and pubertal children, respectively. Expressed as cm/year, these correspond to increases from 3.2 +/- 1.3 cm/year and 4.1 +/- 1.2 cm/year to 8.1 +/- 1.5 cm/year and 8.6 +/- 1.9 cm/year in the prepubertal and pubertal patients, respectively. Safety and tolerance were good and the immunogenicity of Genotonorm was low.