There are few studies about prevalence rate of sensorineural hearing loss with its clinico-audiological evaluation in Korean population. So the author had performed a clinico-statistical analysis on 46112 young adult males, aged 18-24 who had been taken medical check for compulsory military service in Seoul during one year(1984). The following results were obtained from this study : 1) The prevalence rate of sensorineural hearing loss was 0.37%(172 of 46112). Unilateral hearing loss was observed in 74.4% and that of bilateral was observed in 25.6%. 2) The cause of sensorineural hearing loss was unknown in many cases(75.6%), febrile diseases(12.2%), and head trauma(5.2%) in descending order. 3) The onset of sensorineural hearing loss was unknown in 36.0%, but the onset was conjectured before 4 years of age in 21.5%. 4) The degree of hearing impairment was deaf(31.4%), moderate-severe(31.4%), severe(18.0%), moderate, profound and mild in descending order. 5) The audiometric pattern was high tone deafness and flat from in many cases, and in some cases other patterns were observed. 6) There were only 45 cases(25.0%) which were checked to E.N.T. doctors for diagnosis and treatment.