OBJECTIVE The objective of this study is to evaluate the impact of changes to the mucous in the middle ear on the outcome of the reconstruction of the ossicular chain exemplified by a type 2 tympanoplasty. METHODS A prospective analysis was carried out with regard to patients operated on at the Otolaryngology Department at Collegium Medicum, Jagiellonian University, between 2007 and 2011 due to conditions of the middle ear. The patients who had undergone surgical treatment for the first time because of chronic otitis media were taken into account. The operations involving a type 2 tympanoplasty were earmarked for further analysis. The effectiveness of treatment was measured by the change of the Air-Bone Gap (AGP). RESULTS The analysis covered 47 patients, whose own modeled incuses were placed on normal stapes. The patients were divided into two groups (with and without cholesteatoma). A statistically significant hearing improvement was observed in the patients with cholesteatoma. In the group without cholesteatoma and with a prevalence of granulomatous lesions, no statistically significant hearing improvement was observed 6 and 12 months following the ear surgery. CONCLUSIONS In the patients with cholesteatoma and a minor damage to the ossicular chain, a significant hearing improvement is observed after ossiculoplasty. An occurrence of granulomatous lesions is an unfavorable predictor. The Air-Bone Gap measured before the surgery often does not the actual advancement of the pathological process, and hearing improvement after the surgery cannot be prognosticated on the basis of that amount alone.