The presence of Langerhans cells and T cells in human cholesteatoma is demonstrated by immunohistochemical and submicroscopic analyses. Various monoclonal antibodies directed against Langerhans cells and T lymphocytes reveal the presence of these cell populations in the cholesteatoma matrices but not in the normal tympanic membrane. Their quantitative and spatial distribution in and around the cholesteatoma matrix might be of importance in the pathophysiology of human cholesteatoma.