Chronic otitis media is one of the most common disease in the otolaryngologic clinics in Korea. Chronic otitis media refers to chronic suppurative otitis media which suggests otorrhea, tympanic membrane perforation and active irreversible tissue pathology of middle ear cleft. This survey was undertaken to evaluate the status of chronic otitis media in primary school children of Chungnam area from April, 1980 to September, 1980. Total number of 16,457 (Male: 8,209, Female: 8,248) primary school children, consisting of 9,145 from four primary schools in Daejeon city, 2,363 from four in south-west coast and 4,949 from nine in middle south area of Chungnam province were examined by means of otoscopy. Children, that had perforated tympanic membrane with or without discharge, were taken as the subjects in this study. The result were as follows: 1) Overall prevalence rate of COM was 0.826% (136/16,457). There was no significant differrence between ages and sexes, but male was much more prevalent in rural area, on the other hand female was more in urban area. 2) The prevalence rate in each area were 0.580% in Daejeon area, 1.566% in west-south coast and 0.930% in middle-south of Chungnam area. COM was much more prevalent in west-south coast, about 3 times more than in Daejeon city. 3) The prevalence rates in each socioeconomic group were 0.395% in higher group, 0.628% in middle and 1.852% in lower group. Significant difference was noted between the groups; much more prevalent in lower group than in the other groups. 4) The prevalence rate in the groups classified by educational level of parents, was relatively higher in the group with poorly educated parents (1.286% with father, 1.034% with mother) than in the group with highly educated parents (0.624% with father, 0.586% with mother). 5) The age of onset of COM was at 5 years in 20.59%, at 6 in 16.18%, at 7 in 14.71%, at 4 in 13.97%, and at 3 and 8 in 11.03%. On duration of COM, 41.18% of cases had history of 2-5 years, 33.09% over 5 years, 15.44% 1-2 years and 10.29% below 1 year. 6) On otoscopic findings, central perforation was observed in 83.55%, total defect in 11.18% and marginal perforation in 5.26%. Unilateral COM was much more than bilateral, about 7.5 times.