Introduction:
The infracochlear cell tract is a highly variable anatomical space that embryologically develops between the fustis and the finiculus bounded superiorly by the cochlea, anteriorly by the ICA, inferiorly by the jugular bulb and posteriorly by the facial nerve.

Aim of the work:
The aim of this study was to quantitatively and qualitatively assess the radiological and surgical anatomy of the infracochlear tunnel in a sample of the study population at the department of otorhinolaryngology and radiodiagnosis in Alexandria University Hospital, Egypt.

Subjects and Methods:
Cross sectional descriptive study on 50 patients, 41 HRCT examined bilaterally and 6 cardavers
The ICT was present in 52.17% of the study population and 50% of those from the same demographic region. Anatomically type B tunnel was the most prevalent 28/56 (50%), type C were 20/56 (35.71%), and 8/56 (14.29%) had type A tunnel. Radiologically ICT was detected in 43.9%. Type 1 was most prominent and constituted 46/82 (56.10%), 24/82 (29.72%) had a type 2 tunnel, and type 3 and 4 had equal distribution 6/82 (7.32%). There ICT was further measured in its AP and vertical diameters, the vertical diameter was found to be larger (range 0.28-4.09mm) than the AP diameter (range 0.26-3.13mm) in all the groups which was statistically significant.