Ocular involvement after primary infection with varicella zoster virus is very rare. We report a case of a healthy 18-year-old man who presented with unilateral ischemic retinal vasculitis 10 days after the onset of chickenpox. He developed acute severe visual loss and a relative afferent pupillary defect in his right eye. Fundus imaging, optical coherence tomography, fundus fluorescence angiography, and electrophysiologic studies confirmed the diagnosis of retinal vasculitis, which led to generalized retinal ischemia. Although aggressive treatment with systemic steroids and antiviral drugs was administered, a poor visual outcome still resulted.