Data provided by 797 women were analyzed to determine how sexual behavior has changed over time. These women, interviewed in 1983, were originally enrolled as healthy controls for a cervical cancer study. A total of 54.5% of white women and 15.6% of black women had no partners other than their husbands. White women less than 35 years old had twice as many sexual partners during their lifetime (mean of 5.5) as white women greater than or equal to 55 years old (mean of 2.8). Among women greater than or equal to 40 years old, black women had more sexual partners than white women, but among younger women there was little difference by race. Although the number of sexual partners was low compared to homosexual men of the same period, the trends among young women (born 1944 to 1963) to have a higher number of partners and younger ages at the time of first sexual experience indicate that sexual behavior changed in ways that might promote the spread of AIDS and other venereal diseases among women.