Intravenous pump administration (Zyklomat, Ferring) of GnRH (Lutrelef, Ferring) has been used to induce ovulation in 16 patients suffering from hypothalamic amenorrhea between January 1989 and December 1991. One to 6 cycles were performed for a total of 47 cycles. GnRH pulses were set at 20 micrograms/pulse every 90 min up during the follicular phase and decreased to 1 pulse/120 min during the 3-5 days following ovulation. Thereafter, the luteal phase was supported by 1000 IU HCG/48 h up to the end of the 5th week. Response to the treatment was monitored with seriC E2, P and LH and vaginal echography. Cycles (N = 3) were cancelled when E2 did not reach at least 0.25 nmol/l after 30 days. An E2 level > 0.8 nmol/l, associated with a mature follicle (> 20 mm), and the presence of a LH peak or an increased progesterone level were used to determine the day of ovulation. In case of normozoospermy (N = 9), sexual intercourse was recommended to the patients (27 cycles), whereas an intrauterine insemination was performed in case of a male factor (N = 7, 20 cycles). Results can be summarized as follows: 39 (83%) cycles were ovulatory and led to 9 (19%) clinical and 6 (13%) biochemical pregnancies. Five (8.5%) pregnancies aborted and 5 (11%) came to full term. After exclusion of the male factors, the pregnancy rate reaches 26%/initiated cycle, 28%/ovulatory cycle and 56%/patient. No patient developed a hyperstimulation syndrome or a multiple pregnancy. Three cycles (6.3%) were interrupted due to 2 superficial phlebitis and 1 pump failure.(ABSTRACT TRUNCATED AT 250 WORDS)