During the last 4 years we controlled 351 operations in order to check the indication of preservation of the posterior canal wall on patients with cholesteatoma. The aim of this study was to make a comparison between operative technique and the frequency of residual and recurrent diseases. It has shown that the consistent reconstruction of the lateral attic wall by endogenous conchal cartilage reduces the number of recurrences for 15%. Since we haven't got yet a follow-up period of 5 years for all patients, the percentage of recurrent cholesteatomas was forecasted with 16% from the sample of patients with a follow-up period of 2 years. The percentage of residual cholesteatomas was calculated with 25% from 104 revision operations. In future, a planned revision operation seems to be necessary for each patient with a posterior canal wall being preserved in cholesteatoma surgery.