Four patients with human immunodeficiency virus (HIV) infection and central retinal vein occlusion have been previously described in the literature. The pathologic findings in a fifth patient with this association are reported. The histopathologic findings were similar to ischemic central retinal vein occlusion in persons without HIV infections. There was no evidence of HIV in vascular endothelial cells using electron microscopy and in situ hybridization techniques. The failure to identify any structural or direct infectious cause for central retina vein occlusion in this setting suggests that other hemorheologic factors related to HIV infection are probably responsible for the predisposition to vascular thrombosis.