We studied the incidence of exudative otitis media in 488 patients followed up from birth. Forty-nine percent (240) of the patients had their initial episode of otitis media in the first year of life and only 12% (56) in the second year of life. Thereafter, the incidence decreased steadily. Patients having six or more episodes of otitis media before age 6 were termed "otitis prone." Fifty-seven such patients were observed and this condition was found to be significantly related to the onset of otitis media in the first year of life and to the pneumococcal cause of the initial episode.