This study was undertaken to determine whether somatostatin analog in combination with human urinary follicle-stimulating hormone (FSH) improves ovulatory performance in patients with polycystic ovarian syndrome (PCOS) who failed to respond to FSH alone. A comparative prospective study was performed in six insulin-resistant, hyperandrogenic, PCOS women treated with somatostatin analog combined with FSH for one cycle. Individual ovulatory performance was compared to the cumulative ovulatory response of three previous cycles. Somatostatin analog was administered subcutaneously by means of an infusion pump, providing a total daily dose of 200 micrograms starting from days 1-3 of the cycle. Induction of ovulation with FSH was initiated on day 5 of the stimulated cycle. Vaginal ultrasonography for follicular surveillance was performed before the pump setting and during the treatment cycle. A significant decrease in insulin, insulin-like growth factor (IGF-I), growth hormone (GH) and luteinizing hormone (LH) was observed during the combined somatostatin analog-FSH treatment cycles. The follicular growth patterns and the incidence of ovarian hyperstimulation syndrome (OHSS) was not affected. These observations suggest that adjuvant therapy with somatostatin analog may have a beneficial effect on the hormonal response of PCOS patients to gonadotropin induction of ovulation.