OBJECTIVE: The three-dimensional computed tomographic angiography(3D-CTA) images are not commonly used than the conventional digital subtraction angiography(DSA) as a postoperative examination to identify a remnant neck or whether the parent and branching arteries and the cerebral aneurysm are clipped together. We suggest that the neurosurgeons themselves can reconstruct 3D images using 3D reconstruction program in their personal computers and evaluate the aneurysm neck clipping state more precisely than DSA. METHODS: Both 3D-CTA and DSA images were obtained postoperatively on 40 patients with 45 cerebral aneurysms. 38 aneurysms were clipped by single clip, 6 by double clips, and 1 by triple clips. We compared 3D-CTA images, which are made by easy and noninvasive method of the new software to ascertain postoperatively the perfection of aneurysm neck clipping performed with titanium clips, with DSA. RESULT: Out of the total 45 cerebral aneurysms clipped with titanium clips, 3D-CTA clearly showed the state of the clipped necks and the parent and branching arteries of 44 aneurysms in 39 cases. There were three cases in which the remnant necks were found in 3D-CTA, but two of them were not identified in DSA. There was one patient who had cerebral aneurysms requiring 3 clips, resulting in a poor view of the remnant necks since the clips covered the necks. CONCLUSION: In case using one or two titanium clips for the aneurysmal clipping, 3D-CTA may be a reliable alternative method to DSA in the postoperative evaluation to define the cerebral aneurysm neck and the surrounding vessels after clipping.