The authors describe seven patients presenting with ophthalmoscopic findings typical of "presumed ocular histoplasmosis syndrome." However, no humoral antibodies could be demonstrated. Moreover, the results of skin tests were all negative even after "boostering." Hence, the diagnosis of ocular histoplasmosis had to be ruled out. Tests for listeriosis, lues, leptospirosis, ornithosis, Toxocara canis, toxoplasmosis, Larva migrans, and Candida albicans were also negative. There are evidently other, so far unknown, agents which lead to an ophthalmoscopic picture that mimics ocular histoplasmosis with its typical "punched-out lesions" and central hemorrhagic chorioretinopathy. One of these agents may be Epstein-Barr virus, because two of six patients had increased antibody levels of Epstein-Barr nuclear antigen and early antigen, indicating an active or persistent state of viral infection.