Cytomegalovirus (CMV) retinitis is the most frequent ocular infection in AIDS, and it is responsible for blindness. Intravitreal injections of ganciclovir in doses of 400 g have been tried in patients who could not tolerate any systemic treatment. Induction therapy consists of 2 injections per week, followed by maintenance therapy with 1 injection per week. The present study involved 17 patients. Twenty-three induction courses could be evaluated; all had a favourable response with an average of 6 injections per eye. Seventeen maintenance courses were evaluated, with a mean of 5 injections per eye. There was no relapse in 10 eyes (70 percent) at 48 days. There was no evidence of toxicity from repeated intravitreal injections: no cataract, retinal detachment or endophthalmitis was observed with a total of 231 injections. Intravitreal ganciclovir appears to be an effective local treatment of CMV retinitis in AIDS patients when systemic therapy cannot be used.