The dural venous sinuses lie in between the two layers of the dura mater. The dural venous sinuses are important, because they receive blood from the brain and the cranial bones. All sinuses are related to the inner surface of the skull, except for the inferior sagittal and the straight sinus. The sinuses related to the inner surface of the skull produce impressions on it. During routine ostelogical teaching for undergraduate medical students, we observed an unusual oblique sinus, which connected the right and the left transverse sinuses. This unusual oblique sinus measured 2 cm and had a course from the right to the left side. The superior sagittal sinus turned onto the right but at a much higher level than the left transverse sinus. Although these sinuses communicated with each other, the normal position of the confleunce of the sinus (meeting point of superior sagittal sinus, right and left transverse sinus and the occipital sinus) was not seen. The impression meant for the posterior lobe of the left cerebral hemisphere was distinctly greater than that of the right side. The presence of such an anomaly suggests a possible developmental defect or handedness of the individual. The knowledge of the anatomical variations of the dural venous sinuses may have great clinical implications during venography, shunt surgeries and also helpful for neurologists and radiologists in addition to academic interest (Fig. 2, Ref 10) Full Text (Free, PDF) www.bmj.sk.