The autors present a retrospective study of 155 patients, surgically treated for chronic otitis in the years 1996 to 2004 at the Clinic of Otolaryngology and of Head and Neck Surgery in Pardubice. A statistical analysis was performed according to individual observed preoperative factors (sex, presence of cholesteatoma, type of otitis, perforation of eardrum, condition of middle ear ossicles, granulation in middle ear cavity, effusion from ear before the operation, preceding surgery in the area of ear, and smoking) was performed with respect to the state of hearing before and after the operation. According to the evaluation of hearing before and after the operation the very important preoperative negative prognostic factors include presence of cholesteatoma, perforation of eardrum, affected middle car ossicles and preceding type of operation. The less significant negative factors include smoking and type of otitis. The prognostic factors without significance include sex, presence of granulation in middle ear cavity and effusion from ear before the operation.

        Key words: chronic otitis, hearing threshold, cholesteatoma, eardrum perforation, middle ear ossicles, effusion from ear, smoking, statistical, prognostic factors.