We prospectively surveyed the incidence of retinal vein occlusion (RVO) at the glaucoma clinic of Hiroshima University between 1986 and 1991. Among 433 glaucoma patients, 18 (4.2%) subsequently presented with RVO, 9 had central retinal vein occlusion (CRVO) and 9 exhibited branch retinal vein occlusion (BRVO). Seven of 87 (8.1%) patients with primary angle closure glaucoma exhibited RVO, showing the highest incidence among glaucoma types. The incidence of RVO detected by the general outpatient clinic was 0.59% during the same period. The BRVO/CRVO ratio in the glaucoma clinic was 1.0, while it was 4.3 in the general outpatient clinic. Glaucoma is an important risk factor for the development of RVO, especially CRVO.