We studied menstrual abnormalities before and after liver transplantation in 31 women. The incidence of menstrual abnormalities is high before transplantation. Soon after transplantation, in most patients below 45 years of age, the menstrual pattern normalizes. Pregnancy can occur. Consequently, tubal sterilization should be avoided in transplant candidates. After transplantation adequate contraceptive measures should be taken to prevent unwanted pregnancy.