Plasma LH levels in women and female laboratory animals fluctuate. Since catecholamines play a role in gonadotropin secretion, we investigated the possible correlation between catecholamine metabolites and pulsatile patterns of gonadotropin release by measuring two catecholamine metabolites, MHPG and DOPAC. LH levels had a pulsatile pattern, and the levels of MHPG fluctuated. The average of LH and MHPG in polycystic ovary syndrome was significantly higher than that of a normal ovulatory cycle, and the average fluctuation of LH and MHPG in polycystic ovary syndrome was also significantly greater than that in a normal ovulatory cycle. There may be a correlation between the pulsatile pattern of gonadotropin and catecholamine activity, particularly adrenergic activity. It is suspected that adrenergic activity may correlate with the pulsatile pattern in polycystic ovary syndrome.