In the United States, women account for an increasing number and percentage of adults with the acquired immunodeficiency syndrome (AIDS). Overall, 51% of women with AIDS were infected through intravenous drug use and 29% through heterosexual contact; the proportion of intravenous drug users decreased, while the proportion attributed to heterosexual contact increased, between 1986 and 1990. Most women with AIDS were black or Hispanic (72%); residents of large metropolitan areas (73%), especially cities along the Atlantic coast; and of reproductive age (15 to 44 years) (85%). However, the proportion of women with AIDS reported by smaller cities and rural areas has increased from 22% in 1986 to 28% in 1990. The male-to-female ratio of heterosexuals with AIDS has remained about 2.4:1 since 1987. A comparison of women with AIDS to heterosexual men with AIDS showed that these two groups were similar by age, race, and geographic distribution. Also, survival times from AIDS diagnosis to death for women and heterosexual men with AIDS were not significantly different.