Purpose: To investigate the risk of developing retinal vein occlusion (RVO) in patients with psoriasis. Methods: In this retrospective population-based cohort study, 30,198 patients with psoriasis (Psoriasis (+) group) and 30,198 controls without psoriasis (Psoriasis (-) group) between 2001 and 2006 from the Taiwan National Health Insurance Research Database were selected. Results: The incidence of RVO was 1.46 times higher in the Psoriasis (+) group than in the Psoriasis (-) group (3.61 vs. 2.47/10,000 person-years) (adjusted hazard ratio 1.50; 95% confidence interval 1.07-2.10) calculated using Cox proportional hazard regression. Age was an independent risk factor for RVO (adjusted hazard ratio: 11.9 for patients 65 years or older vs. 1.00 for those 0-49 years old). In the 65 years or older Psoriasis (+) group, the incidence of developing RVO was 1.97 times higher (95% confidence interval 1.19-3.26) than in the 65 years or older Psoriasis (-) group. In Psoriasis (+) women, the incidence of developing RVO was 1.82 times higher (95% 1.05-3.14) than in Psoriasis (-) women. For the subgroup with comorbid hypertension, the incidence of developing RVO was 2.07 times higher (95% confidence interval 1.22-3.50) in the Psoriasis (+) group than in the Psoriasis (-) group. Conclusion: Psoriasis was significantly associated with a higher risk of developing RVO.