49 cases of acquired cytomegalovirus retinitis were reviewed including three new cases in renal allograft recipients and one in a patient with Hodgkin's Disease. Diagnosis in over 90% of cases was based on the distinctive funduscopic appearance of cytomegalovirus (CMV) retinitis. When performed, urine, subretinal fluid, and blood buffy coat cultures were positive for CMV in 97, 67 and 39% of cases, respectively. More than two-thirds of these patients were organ transplant recipients who received chronic immunosuppressive therapy. Attempted therapy of CMV retinitis with a variety of regimens has not been proven to be effective. At present, no specific treatment is recommended unless it is given under a controlled therapeutic trial.