The pituitary-ovarian axis was studied in 12 women with a creatinine clearance of less than 5 ml/min per 17 m2, established on regular hemodialysis for at least 12 months. Follicle stimulating hormone (FSH) serum levels were found to be slightly lower than normal, luteinizing hormone (LH) plasma concentration generally elevated, while progesterone and estradiol values were extremely low. The major reproductive consequence of chronic renal failure in women on hemodialysis is a severe impairment in ovulatory function.