Using an immunohistochemical technique and monoclonal antisera, HIV-1 and CMV antigens were demonstrated in lesioned areas of retinal tissues from selected AIDS patients. Polymerase chain reaction (PCR) was utilized to detect HIV-1 and HHV-6 DNA sequences in total retinal tissues from these patients. In this study of six eyes from four patients, two of the retinas contained three different viruses, HIV-1, HHV-6 and CMV. To determine whether HIV-1 and HHV-6 DNA sequences were restricted to the intraretinal lesions, normal and lesioned areas were dissected from the retina, DNA was extracted and subjected to amplification using PCR. The results showed that HIV-1 and HHV-6 DNA were restricted to the lesioned areas. All four lesions (from two different patients) utilized in this study showed the presence of CMV antigens immunohistochemically. The combination of viruses present in each lesion was either HIV-1 and CMV or HHV-6 and CMV. Two of four lesions contained HIV-1 and CMV; a third lesion showed the presence of HHV-6 and CMV. The fourth lesion contained only CMV antigens.