Menstrual abnormalities are common with decreasing renal function and uremia. Maintenance hemodialysis therapy partially corrects some of the abnormalities. Since the pathophysiology of the menstural irregularities is unknown, the secretion of LH, FSH, estrogen, and PRL was studied under basal conditions and after provocative testing in 13 women undergoing chronic maintenance hemodialysis. Elevated LH concentrations were found in all six premenopausal (44.1 +/- 26.4 mlU/ml, normal follicular phase 4 to 30) and seven postmenopausal (246.1 +/- 171.4 mlU/ml, normal 35 to 200) women studied. FSH values were normal both in the premenopausal women (7.9 +/- 4.1 mlU/ml, normal 2 to 20) and in postmenopausal women (88.0 +/- 69.0 mlU/ml, normal 40 to 200). FSH and LH levels did not show typical ovulatory spikes in three of four women studied. Pulsatile hormonal release was absent. The pituitary response to LH-RH was adequate and prolonged, but the response to clomiphene citrate was variable. The study documents the existence of abnormalities at various levels of the hypothalamic-putuitary-ovarian axis.