Background: To describe the prevalence and associations of posterior vitreous detachment (PVD) in a rural adult Chinese population. Methods: All eligible subjects were requested to carry out a comprehensive eye examination; PVD was a prespecified outcome variable and was determined via biomicroscopical examination (slit-lamp biomicroscopy) with a +90-D preset lens after mydriasis. Prevalence was standardized to China population census (2000). Results: 5890 (86.2%) subjects completed the examination of slit-lamp biomicroscopy with a +90-D lens. PVD was present in 160 participants (2.7%); the standardized prevalence was 2.0% (95% confidence interval [CI], 1.6-2.3%). PVD developed increasingly with age (P for trend < 0.001) for both men and women. Using a multivariate regression model, older people were found to run a higher risk of developing PVD than younger people, and women were found to have a higher risk than men (OR, 2.9; 95% CI, 1.5-5.9). Diabetes, hypertension, smoking, drinking, and intraocular pressure (IOP) were not significantly associated with PVD. Conclusions: About one in fifty people is found to have PVD in this population-based study. Age and female are independently associated with PVD occurrence.