To assess the effect of the human immunodeficiency virus (HIV) on mortality in US women 15 to 44 years of age and to identify associated causes of death, we examined final (1980 through 1987) and provisional (1988) national mortality statistics. Between 1985 and 1988, the death rate for HIV/acquired immunodeficiency syndrome (AIDS) quadrupled (0.6 per 100,000 to 2.5 per 100,000), and by 1987, HIV/AIDS had become one of the 10 leading causes of death. In 1988, the death rate for black women (10.3 per 100,000) was nine times the rate for white women (1.2 per 100,000). The majority of deaths in both black and white women occurred in women 25 to 34 years of age, for whom HIV-related deaths accounted for 11% and 3% of all deaths in 1988, respectively. Among 1157 death certificates that included any mention of HIV/AIDS in 1987, other leading diagnoses included drug abuse (27%), Pneumocystis carinii pneumonia (20%), other pneumonias (14%), septicemia (10%), other infections not in the AIDS surveillance definition (7%), nephritis (6%), liver diseases (4%), and anemias (4%). If current mortality trends continue, HIV/AIDS can be expected to become one of the five leading causes of death by 1991 in women of reproductive age. Because women infected with HIV are the major source of infection for infants, these trends in AIDS mortality in women forecast the impact of HIV on mortality in children as well.