After more than 25 years of tympanoplasty for cholesteatomata, it is time to reconsider the origin of this pathological finding. The pathogenesis has not changed, it is the aspects of the disease which have shifted. There are two reasons for this: (a) much improved conditions of living, housing, nutrition and epidemiology, especially during childhood, and (b) discontinuation of the indication for radical surgery, only in the case of threatening complications is tympanoplasty used as a prophylactic operation. In the meantime a new and numerously large group of cholesteatomata has come up which was previously unknown, namely the so-called 'iatrogenic cholesteatomata'. Under these aspects the nomenclature of the cholesteatomata has to be newly defined, according to its etiology and form of disease.