A group of 842 persons were examined with indirect ophthalmoscopy during an epidemiologic study of presumed ocular histoplasmosis in Walkersville, Md. Of 74 cases classified as possible ocular histoplasmosis and further evaluated by two uveitis experts at the Wilmer Institute, 22 cases of ocular histoplasmosis were diagnosed by each independently and without knowledge of the skin test result. The two experts were in close agreement as to the classification of cases. Positive histoplasmin skin tests were found in 59% of the general population, while all 22 subjects with presumed histoplasmosis were positive reactors. Among persons with positive skin tests, 4.4% were found to have presumed histoplasmosis scars. Only one case of disciform macular disease was noted.