The anatomical variations of the intra-cranial venous dural sinuses must be put in consideration in diagnosing magnetic resonance venography (MRV) to avoid the diagnostic pitfalls resulting from over-diagnosis of cerebral venous dural sinus occlusion or thrombosis. The available data regarding the age and sex difference of the magnetic resonance venography (MRV) anatomical variations is still limited. A retrospective study is done for 500 patients ranging from 20 to 70 years. Only 363 patients (142 males and 221 females) were included in our final analysis: all have normal MRI brain & posterior fossa. Magnetic resonance venography (MRV) is done to detect the presence or absence of the transverse venous dural sinuses and to detect any age- or sex-related differences. Also 64 dry Egyptian skulls (41 males and 23 females) were employed to detect symmetry of transverse sulcus and to determine age and sex difference. Hypoplastic left transverse sinus was by far the commonest asymmetrical transverse sinus variants representing 22.0% of total: it was noted in 38 male and 38 female. Even if the asymmetrical transverse sinus is more common in females,