To determine the burden on pediatricians imposed by disease of the middle ear, data from 2570 children, followed up prospectively since birth, were analyzed. Disease of the middle ear accounted for a large proportion of all visits made during the first 5 yr of life, rising from 22.7% during the 1st yr to .apprx. 40% in yr 4 and 5. About 1 visit in 3 made for illness of any kind resulted in the diagnosis of disease of the middle ear. Of all visits .apprx. 3/4 follow up any illness were made to follow up disease of the middle ear. Disease of the middle ear was diagnosed at between 5-10% of all well-baby vists. Children from private practice averaged fewer vists for all reasons than did children using a large neighborhood health center, but the proportions of visits accounted for by disease of the middle ear were similar in both settings.