Triplex (Terumo Co., Tokyo, Japan), a newly developed large diameter vascular graft sealed with a non-biodegradable material, is expected to reduce inflammatory reaction. We confirmed its safe implantation and assessed inflammatory reaction after thoracic aortic surgery. Between January 2009 and February 2010, 101 consecutive patients underwent thoracic aortic replacement. Triplex grafts were implanted in 40 patients, and bovine-collagen coated grafts (Hemashield, Boston Scientific, Boston, MA, USA) were implanted in 61 patients. During the postoperative course, body temperature and laboratory findings including inflammatory markers were examined. The mean operation time and amount of bleeding during operation were equivalent in the two groups. The mean body temperature and C-reactive protein in patients implanted with Triplex were significantly lower than those in patients implanted with Hemashield grafts. The mean white blood cell count tended to be at lower levels in patients implanted with Triplex grafts. No patients in both groups suffered postoperative complications associated with the prosthetic grafts. Triplex was confirmed to be safely applied for thoracic aortic surgery as well as the conventional vascular grafts and to reduce postoperative inflammatory reaction.