Background. Transcatheter aortic valve implantation (TAVI) has emerged as an alternative treatment for high-risk and inoperable patients. Advanced multimodality imaging, including computed tomography (CT), plays a key role for optimized planning of TAVI. Methods. Forty-nine patients (25 women; age, 82.3 +/- 8.8 year) with severe aortic stenosis scheduled for TAVI were examined with 128-slice high-pitch dual-source prospective aortoiliac CT angiography (CTA). The 3-coronary-sinus-alignment (3-CSA) plane, comprising left and right anterior oblique and craniocaudal projection, was defined from three-dimensional volume-rendered technique data sets and compared with the intraoperative angiographic plane (deployment plane) used for device implantation. A tolerance level of +/- 5-degree deviation was acceptable. Volume of intraoperative iodine contrast agent was compared before and after the implementation of the 3-CSA plane estimation by CT. Results. All 49 patients underwent TAVI, during which 6 CoreValves (Medtronic, Minneapolis, MN) and 43 Sapien valves (Edwards Lifesciences, Irvine, CA) were successfully implanted using transapical (n = 29), transfemoral (n = 17), and transaxillary access (n = 4). No severe complications occurred. In 47 patients (96%), CTA correctly predicted the 3-CSA plane used for device implantation. Mean left anterior oblique by CTA was 5.3 +/- 6.5 degrees and craniocaudal was -1.3 +/- 10.1 degrees. Mean left anterior oblique deviation between CTA and the intraoperative projection was 2.1 +/- 2.7 degrees and craniocaudal was 1.7 +/- 3.0 degrees. Ostium heights of the right and left coronary arteries were 12 +/- 1.9 and 12.9 +/- 3.3 mm. No over-stenting occurred in left coronary artery ostia of 8 mm or more. Contrast volume was reduced from 81.8 +/- 25.6 to 59.4 +/- 40.2 mL (p = 0.05) when using 3-CSA plane estimation by CT for final prosthesis implantation plane. Conclusions. Aortoiliac high-pitch 128-slice dual-source CT contributes to TAVI planning, including reliable prediction of the 3-CSA valve deployment plane, which saves contrast volume during the procedure and may facilitate correct valve placement.