A study of 1371 men 20, 30, 50 and 60 years old and living in Göteborg was performed to obtain information on the incidence and prevalence of otitis media in a non-selected population. In addition to anamnestical data, a thorough examination of the ENT-status was made by one observer. There was no indication that otitis media has become a more rare disease since the early part of the century. However, the course of the disease does seem to be shorter and milder in more recent decades. This conclusion is supported by a substantially higher frequency of grave pathologic changes in the tympanic membranes in the two oldest cohorts compared with the two younger. A further indication is that mastoidectomies have become a rare type of operation during recent decades.