Ovarian function has been reviewed sequentially since 1975 in 53 patients treated in childhood between 1942 and 1985 for an intraabdominal tumour with surgery and external abdominal radiotherapy (XRT). Of 38 patients who received whole abdominal XRT (20-30 Gy), 27 failed to undergo or complete pubertal development (pubertal failure) and a premature menopause (median age 23.5 years) occurred in a further ten. Of 15 patients who received flank XRT (20-30 Gy), ovarian function (median age at last assessment 15.2 years) was normal in all but one in whom pubertal failure occurred. In only one patient, who developed pubertal failure after whole abdominal XRT and required sex steroid replacement therapy (HRT) to achieve normal secondary sexual characteristics, has there been evidence of reversibility of ovarian function with a documented conception at the age of 22.7 years. Five patients who developed pubertal failure required bilateral augmentation mammoplasties despite sex steroid replacement therapy. Four patients have had documented conceptions, all received whole abdominal XRT (20-26.5 Gy) and subsequently developed a premature menopause. There have been no live births, with all miscarriages occurring in the second trimester. The outlook for normal ovarian function following whole abdominal XRT is poor, flank XRT introduced intermittently from 1972, has resulted in less pubertal failure but the possibility of a premature menopause may with time become a reality.