Very little information exists on racial differences in quality of life among older adults. In this paper, we examine black-white differences in health-related quality of life (HRQOL) and identify factors that may account for these differences. The participants were 5,986 community-dwelling persons age 65+ (62% black at baseline) from the Chicago Health and Aging Project. Poor HRQOL was defined as having 14 or more self-reported physically or mentally unhealthy days over the past 30 days. A higher proportion of blacks (11.0%) than whites (9.7%) reported poor HRQOL. After adjusting for age and sex, blacks had increased odds of reporting poor HRQOL compared with whites (odds ratio [OR] = 1.72; 95% CI: 1.50-1.98). The black-white differences in HRQOL tended to increase with age (p < 0.05) and were greater among females (p < 0.05). Lifetime socioeconomic status, summary measures of medical conditions, and cognitive function accounted for most of the black-white difference (OR = 1.06; 95% CI: 0.89-1.27). Our results suggest that racial differences in HRQOL are associated with the combined effects of social disadvantage, poor physical health, and lower cognitive function.