Epidemics of viral conjunctivitis are a major public health problem in the Far East. No treatment has been shown to shorten the duration of illness. We studied the clinical course of epidemic keratoconjunctivitis in 74 patients during an outbreak of nearly 3,000 cases in late 1988 at a U.S. military base in the Philippines. Patients were randomly assigned to treatment with trifluridine, dexamethasone, or artificial tears, and examined in a doublemasked fashion. There was no significant difference between the results of the three treatments. No bacterial cultures were positive. The prompt use of patient isolation, identification of nonadenoviral red eyes, and symptomatic treatment without steroids, antiviral, or antibiotic medication is recommended in cases of epidemic keratoconjunctivitis. This is the largest series of cases of epidemic keratoconjunctivitis with laboratory confirmation reported from the Philippines.