Using pulsatile LH-RH administration, ovulation induction was performed in women with pituitary dwarfism (PD, n = 1), isolated gonadotropin deficiency (IGD, n = 5), secondary hypothalamic amenorrhea (gestagen negative (AM2, n = 10), positive (AM1, n = 5)), polycystic ovarian disease (PCO, n = 6) and anovulatory cycle (ANOV, n = 1). Five to 20 micrograms of LH-RH was administered subcutaneously with a pulse frequency of 90 min to 2 h, in 76 treatment cycles. The ovulation rate of IGD, AM2, AM1 and PCO was 54.5, 83.3, 12.5 and 50.0%, respectively, all being significantly different from each other. In some cases, ovulation induction was repeated for several cycles without any interruption, and chronic effects of this therapy on the subsequent cycle were examined. In IGD and AM2, subsequent cycles were well stimulated, while those of PCO became refractory. These results indicate that pulsatile LH-RH administration should be the first choice of ovulation induction in IGD and AM2, and less effective in AM1 and PD. When this treatment is applied for PCO, the luteal phase should be supported by alternative methods to avoid pituitary desensitization.