Sixty-seven-year-old male with a distal aortic arch aneurysm was evaluated by spiral CT with three-dimensional reconstruction. Spiral CT allows rapid data acquisition through an entire anatomic region during a single breath hold. The helically acquired data undergo interpolation. Transverse images are reconstructed with slice intervals 1-4 mm apart. Three-dimensional images were generated by these data with the transverse images. The entire anatomical correlation with the aneurysm and the aortic arch branches was clearly recognized by these three-dimensional images. Preoperative evaluation of the distal aortic arch aneurysm by spiral CT with three-dimensional reconstruction was useful for the surgical treatment.