Objective: the aim of this study is to describe the extension of unsafe middle ear disease in the sinus tympani and to review the methods of surgical access to remove the disease from this area.

 Methods: Of the 164 operated ears with unsafe chronic suppurative otitis media 64(39%) ears had variable disease extension into the sinus tympani and were included in the study. Sixty-two ears underwent canal wall down (CWD) procedure while remaining two underwent tympanoplasty with bone work.

 Result: Five operated ears had deeper extension of the disease into the sinus tympani. And despite of different maneuver the complete removal of the disease could not be confirmed. Six ears (9.4%) had recidivism.

 Conclusion: The study emphasizes on the greater incidence of this disease extension into this difficult anatomical area and their complete removal may not be always possible. But one should require thorough knowledge and surgical expertise to work in this difficult area of posterior mesotympanum.