The etiology and pathophysiology of chronic otitis media with cholesteatoma are not clearly understood but it is very important disease entity from the clinical point of view because it causes destruction of surrounding bone including ossicles and induces not only severe conductive hearing loss but hazardous otogenic and intracranial complications such as labyrinthitis, facial palsy, meningitis, lateral sinus thrombophlebitis and cerebral abscess. Author performed the clinical study in 187 cases of chronic otitis media with cholesteatoma operated from Sep. 1983 to June 1988 at Department of Otolaryngology of Guro Hospital, Korea University. After reviewing and comparing the clinical characteristics, operative findings and operative methods, we obtained the following results. 1) Sex and site distribution showed no significant difference and age incidence was highest in 3rd decade as 47.3%. 2) The most frequent complication was subperiosteal abscess on the clinical findings and dura exposure on the surgical findings. 3) The characteristic of the preoperative hearing impairment was almost conductive in type and moderately severe hearing loss in degree. 4) Most cholesteatoma extended to epitympanum and antrum and cholesteatoma extended more sevely in children than in adults. 5) The greater extension of cholesteatoma was associated with higher detection rate in temporal bone X-ray, more severe hearing loss and total durm perforation. 6) There was no significant difference in improvement of hearing between open technique(34.7%) and closed technique(31.8%). 7) The most common postoperative complication was wound infection and the most frequent cause of postoperative failure was persistent otorrhea.