Both technical and clinical implications of three-dimensional computed tomographic angiography in the evaluation of intracranial circulation, and in particular cerebral aneurysms, are presented. Three-dimensional computed tomographic angiography allows excellent visualization of the aneurysm, its neck, and its relationship with the parent artery and important adjacent bony structures. This technique has a major role in the evaluation of difficult aneurysms. In addition, advantages and disadvantages are discussed in comparison with more conventional techniques such as magnetic resonance imaging, magnetic resonance angiography, and digital subtraction angiography. Three-dimensional computed tomographic angiography will continue to develop with the advent of more rapid computed tomography scanners, playing a key role in the investigation and screening of patients with a family history of cerebral aneurysms.