Basilar aneurysms that are not amenable to standard endovascular treatment via the femoral approach because catheterization is difficult pose a rare but serious problem. We present two cases of basilar tip aneurysms successfully treated by the endovascular route after direct puncture of the right vertebral artery. In both patients, the left vertebral artery was tortuous, small, and irregular, and the ostium of the right vertebral artery was not accessible by the femoral approach.