Each of 14 anovulatory patients received a single injection of 150 micrograms of synthetic luteinizing hormone-releasing hormone (LH-RH) in one induced menstrual cycle. In two subsequent cycles, patients were pretreated with clomiphene before LH-RH injection. Four patients received LH-RH after pretreatment with human menopausal gonadotropin (HMG) in another cycle. In each cycle, gonadotropin release and ovulation were recorded. All patients had previously failed to ovulate when treated with large doses of clomiphene. No patient ovulated following injection of LH-RH alone, although five patients exhibited a good pituitary response. Nine patients ovulated when they received LH-RH after pretreatment with clomiphene, and one patient ovulated when pretreated with HMG. The diagnostic value of a single injection of LH-RH is not clear. In the present study, gonadotropin response to LH-RH was not an entirely accurate predictor of a patient's ovulatory response in any of the four cycles. On the other hand, when clomiphene-LH-RH was administered, a good response was associated with ovulation in that cycle. The exact role of LH-RH in inducing ovulation is unclear, but the results of using LH-RH in conjunction with clomiphene are encouraging enough to warrant continued use and further study.