PURPOSE: To assess the prevalence of glaucoma in adult Chinese. DESIGN: Population-based study. METHODS: The Beijing Eye Study in 2001 included 4439 subjects with an age of 40+ years. Glaucoma was determined using the ISGEO (International Society of Geographical and Epidemiological Ophthalmology) classification scheme. RESULTS: Glaucoma was detected in 158 subjects (3.7%, 95% confidence interval [CI] 3.1%-4.2%), in which open-angle glaucoma (OAG), primary angle-closure glaucoma (PACG), and secondary glaucoma (SG) accounted for 2.6% (95% CI 2.1%-3.0%), 1.0% (95% CI 0.7%-1.3%), and 0.07% (95% CI 0%-0.1%), respectively. The overall glaucoma prevalence for the age groups of 40 to 49 years, 50 to 59 years, 60 to 69 years, and 70+ years was 2.2%, 2.5%, 4.4%, and 9.5%, respectively: Glaucoma prevalence increased significantly with age (P = .001), myopic refractive error (P < .001), and intraocular pressure (P < .001). The age-standardized prevalence of OAG, PACG, and SG was 2.5%, 1.0%, and 0.1%, respectively. Prevalence of glaucoma-related bilateral blindness or unilateral blindness was significantly (P = .02 and P = .03) higher in PACG than in OAG. Frequency of glaucoma-associated blindness and low vision was significantly higher in the rural area than in the urban region (6/62 vs 2/96, P = .04). CONCLUSIONS: In the adult population of Greater Beijing, glaucoma prevalence was 3.6% and increased with age, myopic refractive error, and intraocular pressure. Glaucoma prevalence of 3.6% was comparable with figures from Caucasian populations. The ratio of OAG to PACG of 2.6:1 agrees with recent other studies from East Asia. Glaucoma-related blindness and low vision occurred significantly more often in PACG than in OAG. (Am J Ophthalmol 2010;1.50:917-924. (C) 2010 by Elsevier Inc. All rights reserved.)