In 1980-1985 680 preadolescent tall girls were treated with pharmacological doses of oestrogen to reduce final height. Indications for the therapy were predicted final height greater than +2.5 SD (180.75 cm), idiopathic scoliosis, and psychosocial problems. Until 1976 141 girls were given diethyl stilboestrol 5 mg daily. By advice of Prader this was then replaced by ethinyl oestradiol and a progestin was given on days 5-10 each month. The mean duration of therapy was close to 2 years. The observed short-term unwanted effects were due to the pharmacological actions of the drugs, (11 girls had galactorrhoea at the end of therapy; no pituitary prolactinoma was observed) or events happening by chance.