A total of 66 eyes in 41 patients were treated for cytomegalovirus (CMV) retinitis with a new acyclic nucleoside, ganciclovir (BW B759U). At the completion of the short-term therapy period of 21 days, 87.7% of eyes had stabilized or improved. Seventy-two percent of eyes stabilized or improved during long-term home maintenance therapy. Leukopenia and increased liver function abnormalities were the most common adverse drug reactions seen in this series. Ganciclovir dramatically improved the quality of life in these patients, but clinical evidence suggests that it is a virostatic medication requiring indefinite long-term maintenance therapy.