Purpose: To report the prevalence and risk factors associated with primary open-angle glaucoma (POAG) in the Kandy district of central Sri Lanka. Methods: A cross-sectional, population-based ophthalmic survey of the inhabitants ≥ 40 years of age from villages in the Kandy District, Sri Lanka was conducted. Selection was randomized using a cluster sampling process; 1721 eligible participants were identified, 1375 participated in the study and sufficient examination data to diagnose glaucoma in at least one eye was obtained in 1244 participants. A detailed ophthalmic history and examination including ocular biometry was made of each participant. Primary open-angle glaucoma was classified into three levels according to diagnostic evidence. Results: The overall prevalence of POAG was 2.3% (95% CI 1.5–3.2). In the univariate analyses, increasing age ( P = 0.001), intraocular pressure (IOP) ( P < 0.001), myopia ( P < 0.001) and axial length ( P = 0.003) were significantly associated with POAG. In the multivariate analysis, age ( P = 0.001), mean IOP ( P < 0.001) and mean axial length ( P = 0.008) were significant risk factors of POAG. Conclusions: The prevalence of POAG in the population aged ≥40 years in central Sri Lanka was 2.3%. POAG in this population was independently associated with increasing age, IOP and axial length. [ABSTRACT FROM AUTHOR]