Aim:The brain venous drainage dominancy was generally divided into three groups; right or left dominancy and co-dominancy. Our aim in this study was to evaluate the association between venous dominancy and aneurysm formation and rupture. There is no study in the literature examining the link between brain venous drainage and aneurysm formation or rupture.Material and Methods:Eighty-six patients, who underwent cerebral digital subtraction angiography and who had cerebral aneurysms, were included to the study. The angiographic images, patient’s charts, and tomography images were scanned retrospectively. We recorded the aneurysm’s location, size, dome to neck ratio (D/N); patient’s gender, ages, whether they had ruptured aneurysm, smoked, and/or had hypertension; dominancy of venous drainage, aneurysm sides, Fisher scores and the World Federation of Neurological Surgeons Grading System for Subarachnoid Hemorrhage (WFNS) scores for patients who had ruptured aneurysm. We assessed whether or not venous drainage is associated with rupture of the aneurysm and if venous dominancy is a predisposition factor for aneurysm formation like location, size, and hypertension. Results:There is a statistically significant association between venous dominancy and sides of aneurysm; and also a statistically significant association between venous dominancy and rupture. There is a positive correlation between hypertension and rupture. The most common aneurysm location is on the anterior communicating artery, followed by the middle cerebral artery.Conclusion:Brain venous drainage dominancy may be a predisposition factor for aneurysm formation and it can be a predictive sign for rupture.