Prior studies of the association between socioeconomic status and length of survival among persons infected with the human immunodeficiency virus (HIV) have produced conflicting results. To investigate this issue further, the authors examined data on 18,167 San Francisco, California, residents aged 13 years or older who were diagnosed with acquired immunodeficiency syndrome (AIDS) between January 1, 1985, and December 31, 1995. Three validated US census-based measures of socioeconomic status were used: poverty, predominantly working class neighborhood, and low educational level. Median length of survival was found to be similar for persons living in neighborhoods characterized by poverty (22 months) and those in higher income neighborhoods (23 months), for persons living in predominantly working class neighborhoods (22 months) and those in predominantly professional/managerial neighborhoods (23 months), and for persons living in neighborhoods characterized by low educational level (23 months) and those in neighborhoods characterized by higher educational level (23 months). After adjustment for sex, age, ethnicity, AIDS risk group, site of AIDS diagnosis, time period of AIDS diagnosis, and AIDS-indicator illness, no association was found between survival and living in a neighborhood characterized by poverty (relative hazard (RH)=1.03, 95% confidence interval (CI) 0.97-1.08), between survival and working class occupations (RH=1.03, 95% CI 0.98-1.08), or between survival and low educational level (RH=0.96, 95% CI 0.90-1.01). The lack of an association between socioeconomic status and length of survival with AIDS may be due to the high mortality from AIDS in the era prior to highly effective antiretroviral therapy or to similar levels of access to care in San Francisco.