Three-dimensional CT angiography is a new modality for minimally invasive vascular imaging. Meticulous attention to technique is critical to optimizing image quality and achieving diagnostic images. In this article, the properties of spiral CT acquisitions, intravenous contrast delivery, and three-dimensional rendering techniques, as they pertain to the optimization of CT angiograms, are discussed. Next, a review of initial investigations into the clinical applicability of CT angiography in the cranium, neck, chest, abdomen, and pelvis is provided. Finally, CT angiography is compared with MR angiography and conventional angiography.