OBJECTIVE: To determine the prevalence of glaucoma among black and white persons 73 years and older. DESIGN: Participants in the fourth round of a population-based study, the Salisbury Eye Evaluation, were examined. The main outcome measure was glaucoma, based on optic nerve damage and visual field loss or obvious glaucomatous optic neuropathy without an available, reliable, reproducible visual field. RESULTS: A total of 1250 individuals (95.9% of those eligible) participated, 1233 (98.6%) of whom agreed to screening and an eye examination. The prevalence (95% confidence interval) of open-angle glaucoma was 3.4% (0.5%-6.4%) for white individuals aged 73 and 74 years, increasing to 9.4% (7.4%-11.5%) for those 75 years and older. There was no increasing prevalence in those older than 75 years. Among black persons, the prevalence (95% confidence interval) was 5.7% (0%-11.9%) in those aged 73 and 74 years and 23.2% (17.8%-28.5%) in those 75 years and older. CONCLUSIONS: Many older individuals have open-angle glaucoma, and black persons 75 years and older have substantially higher rates than whites. These findings have important implications for public health initiatives, in which screening programs may be of benefit.