To compare trends in the length of survival for women and men after diagnosis of AIDS, data were analyzed for 139 women and 7045 men who were reported with AIDS in San Francisco between July 1981 and 31 December 1990. Patients were followed prospectively through 15 May 1991. The median survival for women (11.1 months) was significantly shorter than that for men (14.6 months). When data were stratified by year of diagnosis, significantly improved survival was observed in recent years for both women and men, although survival for women remained significantly shorter than that for men. Among those who received either zidovudine or 2′,3′dideoxyinosine, survival did not differ by gender. However, among those not receiving therapy, survival was significantly shorter for women. These results suggest that the shorter survival of women may be a result of factors other than gender, possibly including less use of antiretroviral therapy.