Ten patients with hypothalamic anovulation were treated with a “retard” preparation of synthetic luteinizing hormone releasing hormone (LHRH) after an HMG stimulation in order to induce ovulation and pregnancy. Four of the patients ovulated after intramuscular administration of the LHRH preparation. This study suggests that it is possible to induce ovulation with LHRH in patients pretreated with HMG, and that LHRH has advantages over HCG since it does not induce hyperstimulation even in the presence of exaggerated follicular growth. Nevertheless, the optimal conditions for the use and monitoring of LHRH treatment have yet to be clarified.