Urinary excretion of steroid hormone metabolites pregnandiol, pregnantriol, aetiocholanolone, dehydroepiandrosterone and androsterone of 20 patients with Turner's syndrome was measured by gas chromatography. In some of the patients urinary excretion did not reach the minimal value obtained in a control group. Sixteen of these patients were given an average daily dose of 0.1 mg oxandrolone/kg body-weight. Mean value for bone age, after an average treatment duration of 17.3 months (s = 9.7), increased by 12.6 months (s = 12.7). Growth rate was 5.9 cm (s = 1.9) per year. Androsterone and dehydroepiandrosterone excretion in patients in whom the chronological age/bone age ratio had worsened, was more than double that in patients in whom it had improved. Measurement of the urinary excretion of dehydroepiandrosterone and androsterone thus seems to be of prognostic value in the treatment of Turner's syndrome with androgens.