PURPOSE: To describe a patient with occlusive, retinal vasculitis and concomitant, confirmed, acute West Nile virus (WNV) infection. DESIGN: Observational case report. METHODS: Main outcome measures included comprehensive ophthalmic examination with fluorescein angiography, color photography, and serologic testing for WNV and St. Louis encephalitis (SLE) virus including plaque reduction neutralization testing (PRNT). RESULTS: A 46,year,old woman developed a sudden de, crease in vision in her left eye 2 weeks after confirmed WNV infection and demonstrated multiple, small, patchy areas of retinal edema with scattered microaneurysms. Fluorescein angiography showed multiple branch artery occlusions with extensive nonperfusion. Serologic titers for WNV were positive for acute infection. Plaque reduction neutralization testing confirmed WNV infection and excluded St. Louis encephalitis virus infection. Other etiologies of occlusive vasculitis were not present. CONCLUSION: Occlusive, retinal vasculitis may occur in the setting of acute WNV infection.