A 51-year-old man presented with subarachnoid haemorrhage with mild hydrocephaly. Digital substraction angiography and 3-D Computerised Angiogram (CT) revealed a saccular aneurysm at bifurcation of azygos anterior cerebral artery (ACA) and other vascular variations such as vertebral artery fenestration and hypoplasia in one anterior cerebral artery. We performed aneurysmal neck clipping with good outcome and postoperative 3-D CT angiogram showed complet obliteration of aneurysm. Although azygos arteries are rare in healthy population, aneurysms of azygos ASA are not rare due to increased haemodynamic stress. We wanted to point out to better visualisation of anatomical variations at 3-D CT angiogram comparing DSA in patients with intracranial aneurysm.