The present study was undertaken to verify the efficacy of preparations for inducing follicular maturation and ovulation in patients with polycystic ovary syndrome (PCOS). Successful induction of ovulation in patients with PCOS was observed in treatment cycles with daily injections or pulsatile subcutaneous administration of human menopausal gonadotropin (hMG), the combination of clomiphene citrate and bromocriptine, or the combination of clomiphene citrate and hMG. The incidence of ovarian hyperstimulation syndrome varied with the different clinical conditions in which ovulation was induced, the types of preparations administered, and the doses and schedules administered.