Between 1979 and 1990, 73 patients suffering from hypothalamic amenorrhoea were treated by pulsatile administration of gonadotrophin releasing hormone (GnRH) in 359 treatment cycles. Seventy-two pregnancies were achieved. In 64 favourable patients in whom hypothalamic amenorrhoea constituted the only reason for infertility, a pregnancy rate of 29% per cycle could be obtained. Patients who conceived during pulsatile GnRH required an average of only 2.4 cycles per conception. Twelve out of 24 patients with hypothalamic amenorrhoea who exhibited an ovulatory response to pulsatile GnRH, ovulated during oral administration of naltrexone; such responsiveness to opioid antagonism was, however, restricted to the less serious grades. In conclusion, pulsatile administration of GnRH continues to be a highly effective mode of treatment of infertility due to hypothalamic amenorrhoea of various aetiologies. A subgroup of these patients may be successfully treated by the oral administration of naltrexone.