So-called external auditory canal cholesteatoma is not a rare disease, but the etiology is not clear. Keratosis obturans and external auditory canal cholesteatoma have been considered to be the same disease. However, recently Piepergerdes reported that keratosis obturans and external auditory canal cholesteatoma are two different clinical and pathological processes, the former being characterized by a dense plug of keratin debris within the deep meatus and inflammation of the subepithelial tissue. Recovery is usually complete with conservative treatment. On the other hand, external auditory canal cholesteatmoa is characterized by a localized erosion of the deep canal wall with localized periosteitis and sequestration; it usually requires operative treatment.We describe here two cases of so-called external auditory canal cholesteatoma which we considered to be keratosis obturans and discuss the differences between external auditory canal cholesteatoma and keratosis obturans reported in the literature.Clinical differentiation between external auditory canal cholesteatoma and keratosis obturans is important since the treatment is different.