To prevent coil protrusion into the parent artery, the fluoroscopic view during coil packing is quite important. However it is not always easy to find out the optimal fluoroscopic view. We applied a rotation DSA to predict the optimal fluoroscopic view for the endovascular treatment of 4 cases with a cerebral aneurysm. Since the trajectory of the C-arm is restricted within 60 degrees only around the patient's head and the number of DSA shots are limited rather than conventional DSA, we employed three dimensional CT angiography (3D-CT angiography) to focus the range of C-arm rotation. Rotation DSA proved quite useful to determine the optimal fluoroscopic view, when combined with pre-estimation by 3D-CT angiography.