The treatment of clinically resistant cytomegalovirus retinitis in AIDS patients requires a combination of foscarnet and ganciclovir, but the poor clinical condition of some patients may weigh against this intravenous regimen. We treated three patients with high-dose intravitreal foscarnet (2400 micrograms/0.1 ml; 25 injections; mean follow-up 14.6 weeks) combined with intravenous ganciclovir (5 mg/kg twice daily), and obtained complete control of the retinitis in a mean time of 3.4 weeks with no ocular or systemic side effects and no other eye/organ cytomegalovirus dissemination. This combined therapy seems useful for clinically resistant cytomegalovirus retinitis in AIDS patients.