A large percentage of patients in stage IV of HIV infection (CDC classification) show changes in the ocular fundus. Most frequent are functionally unimportant cotton-wool spots resulting from a HIV-associated microvasculopathy. Infectious retinitis due to opportunistic organisms is in most cases caused by cytomegalovirus (CMV). Untreated patients may become blind. In case of general or local treatment of cytomegalovirus retinitis with ganciclovir, sight may be preserved on a long-term basis. The ophthalmoscopic appearance of the typical changes and their histological substrate are presented, and modes of treatment are discussed. By direct ophthalmoscopy and visual acuity testing any physician can diagnose these fundus changes. Cotton-wool spots only require follow-up. In retinitis an ophthalmologist should be consulted. A screening procedure is suggested.