Cytomegalovirus retinitis (CMVR) is a severe, vision-threatening disease that primarily affects immunosuppressed patients. CMVR is the most common ocular opportunistic infection in human immunodeficiency virus (HIV) infected patients and is the leading cause of blindness in this group; however, the incidence of CMVR in HIV patients has dramatically decreased with antiretroviral therapy. Other causes of immunosuppression, including organ transplantation, hematologic malignancies, and iatrogenic immunosuppression, can also lead to the development of CMVR. Herein, we describe the pathogenesis of CMVR and compare clinical features, epidemiology, and risk factors in HIV and non-HIV infected individuals with CMVR.