In the early nineties, the stentless porcine aortic bioprosthesis has been reintroduced successfully. Because of the limited experience, knowledge of clinical complications is limited. Therefore, we describe an unusual complication of dynamic obstruction after aortic valve replacement with a stentless porcine valve in a 70 year old man 18 months after implantation. We discuss the complications of stentless aortic prostheses known so far, describe operative techniques used and their characteristic two dimensional echocardiographic images.