We did a long-term follow-up study of 42 patients aged 40 years and younger who had occlusion of the central retinal vein in order to learn its course and determine the frequency of related systemic disorders. Two groups of venous occlusion (complete and incomplete) were delineated by initial ocular findings. Final visual prognosis could not be predicted by the severity of the venous occlusion at the time of diagnosis. The presence of anomalous disk vessels closely correlated with a favorable prognosis in patients who had complete occlusion of the central retinal vein. None of the patients with incomplete central vein occlusion developed neovascular glucoma; three (14%) of the 21 patients with complete venous occlusion developed neovascular glucoma, which resulted in enucleation. Significant associated systemic maladies included cardiovascular disease and diabetes mellitus. An apparent correlation exists between occlusion of the central retinal vein and early death.