AIM: To report the epidemiology and incidence of vitreous hemorrhage and to evaluate risk factors for patients with vitreous hemorrhage (VH) in Taiwan. METHODS: A retrospective population-based study. Analyzing a sample of one million subjects from all enrollees of the Taiwan Health Insurance programme. All data were obtained from the Taiwan Health Insurance Research Database, which contained patient sex, date of birth, all records of clinical visits and hospitalizations, and diagnosis codes as included in the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM). The main outcome measures were the incidence and risk factors of VH. CONCLUSION: The incidence of VH is estimated being 4.8 cases per 10 000 person-years in Taiwan. Age, male gender and having been prescribed anti-coagulation drugs are associated with the incidence of VH.