The efficacy of ovulation induction with the use of pulsatile gonadotropin-releasing hormone (GnRH) therapy was examined in 21 infertile women. Seventeen had hypothalamic amenorrhea (HA) and 4 polycystic ovary syndrome (PCO). All patients were treated as outpatients. GnRH was infused in a pulsatile mode by means of portable auto-infusion pumps connected to an indwelling intravenous catheter inserted into a forearm vein. The doses varied from 1.8 to 5 micrograms/pulse with a frequency of 90 minutes. Ovulation occurred in 52 out of 64 cycles (81.2%). Ten (47.6%) of the 21 patients became pregnant. Seven patients had normal term deliveries and 3 aborted spontaneously. With regard to the 17 patients with HA, ovulation occurred in 93.7% of treatment cycles and 6 women became pregnant. In the case of the PCO patients, ovulation was achieved in 6 out of 15 cycles (40%) and 2 women became pregnant. There was no overstimulation or any other serious complication. In conclusion, therapy with GnRH provides an elevated probability of therapeutic success, especially in HA.