Ultrastructural evaluation is a tool which provides useful information which can lead to understanding of the different physio-pathological mechanisms involved in various otological disorders. After a short review of the procedures presently available for histopathology of human temporal bones from cadavers and indication of their related problem, the authors define the pros and cons of intra-operative biopsies of the membranous structures of the inner ear. The different histopathological methods are presented which may be applied on each specimen along with some technical details which make their use feasible for any otoneurosurgical center. The different membranous inner ear structures are taken into consideration; structures which can be approached by different otoneurosurgical procedures. Emphasis is placed on some technical hints to minimize artifacts. Finally, a more continuous, widespread use of intra-operative biopsies is proposed in order to obtain a fairly large amount of specimens as this would contribute to elucidate the unresolved problems inherent to many otological disorders.