The histories of 113 patients with Reiter's syndrome were reviewed to obtain information regarding the sequence of the clinical signs and symptoms, laboratory findings, and progression of disease. Rheumatologic manifestations occurred in 98% of the patients, genitourinary manifestations in 74%, ophthalmic manifestations in 58%, and mucocutaneous manifestations in 42%. Four major criteria and six categories of minor criteria for the diagnosis of Reiter's syndrome, based on the frequency and specificity of the various manifestations of the disease, are proposed. The ophthalmic and nonophthalmic features are important to appreciate because the ophthalmologist is frequently at the pivotal point in suggesting or supporting the diagnosis.