Aim: The aim of this study was to investigate the sphenoidal sinus septation and extension in a sample of Egyptian population. Subjects and methods: A total of 51 CBCT scans were included in this study. Age range was from 18 to 50 years. The SS were assessed regarding the configuration type, clival extension, and anterolateral and posterior extension. The association of the different assessed variables with sex and age was analyzed. Results: Septations were revealed in 98% of cases. The most common type was compound type followed by paired type. The most common form of the clival extension was subdorsal type then the occipital type and finally the dorsal and the combined types. Concerning the anterolateral extension 21.6% showed bilateral extension and 9.8% showed unilateral extension. Non-critical type of posterior extension was revealed in 78.4% while the critical type was reported in 21.6%. There was no statistically significant difference between sex and age, and configuration type of the sinus or pneumatization into clivus. Conclusion: The high variability of the SS requires an extensive knowledge and understanding of the sinus anatomy to protect the vital structures surround it and CBCT is an ideal choice for the sinus examination before surgical procedures