Transcatheter aortic valve implantation (TAVI) is a relatively mature technique that is generally accepted as a promising treatment for inoperable patients and those who are high-risk candidates for surgical aortic replacement. Although severe complications in the aortic valve complex, such as annular or aortic root rupture, are not frequently observed, these events could easily lead to catastrophic outcomes, and therefore remain major issues during TAVI. However, there remains a paucity of data describing these catastrophic complications because of their low incidence. We encountered the case of an 88-year-old woman complicated by a dissection of the ascending aorta during TAVI from an “unusual” cause: injury due to the delivery of a balloon-expandable valve to a very narrow and heavily calcified sinotubular junction (STJ). This is the first report to demonstrate the mechanism of this complication; even a delivery balloon, not a stent frame, with low inflation pressure might injure a narrow STJ and lead to an aortic dissection. Therefore, the use of oversized delivery balloons should be avoided in patients with a narrow and calcified STJ. © 2015 Wiley Periodicals, Inc.