To determine whether the quantitative and qualitative aspects of GH secretion in girls with Turner's syndrome are similar to those of short-normal children we studied the 24-h GH secretion of 10 patients with Turner's syndrome and 9 short-normal children with comparable auxological features. GH profiles, obtained by 30-min sampling, were analysed by the Pulsar programme. The pulsatile GH release over the 24 h in Turner's syndrome was similar to that in normal children. However, when the GH release over the 12 day and night hours were separately analysed, only normal children showed a night-time increase in the sum of peak amplitudes. Moreover, patients with Turner's syndrome had significantly decreased number and frequency of peaks in the night-time compared with short children. In short-normal children but not in Turner's syndrome, height velocity was related to the 24-h integrated concentration of GH, area under the curve over zero-line and over baseline, sum of peak areas, and amplitudes. Night-time GH area over zero-line and over baseline, mean peak amplitude, height area, sum of peak area and amplitudes were positively correlated with height velocity in short children, whereas in Turner's syndrome height velocity was related to daytime parameters only. In conclusion, girls with Turner's syndrome have a discrete pattern of pulsatile GH release. However, the relation of GH secretion to growth in these patients, is uncertain.