Malfunction of a prosthetic aortic valve is associated with a spectrum of potentially life threatening complications. In addition, the risk of aortic dissection increases following aortic valve replacement, which relates principally to aortic root pathology rather than prosthetic type or its functional status (Circulation 100 (1999) II-287). We report a case in which a high velocity turbulent jet in the proximal aorta, resulting from prosthetic leaflet entrapment caused intimal injury with subsequent type I dissection. This highlights the desirability for regular surveillance following aortic valve replacement, particularly in those patients with an 'at-risk' aorta.