Although some information is available about the risk of liver tumors associated with combined oral contraceptive use, little is known about the relationship with other hepatic problems. Data from two large long-term observational studies, the Royal College of General Practitioners (RCGP) Oral Contraception Study and the Oxford-Family Planning Association (Oxford-FPA) Study, were used to examine this issue. Observations accumulated over a period of up to 27 years were available for each study. The incidence of liver disease in each study was low. There was no evidence of an increased risk of serious liver disease overall among current or former pill users. The RCGP study found a modest increased risk of mild liver disease associated with oral contraceptive use which declined after four years of use and after cessation of use. This increased risk occurred in women who had used oral contraceptives containing more than 50 micrograms of estrogen.