Prosthetic valve dysfunction is a rare but life-threatening condition. A 66-year-old woman presented with shock 15 years after aortic valve replacement with a tilting-disc valve. Imaging demonstrated severe aortic insufficiency and a fixed-open prosthetic valve. Reoperation revealed pannus ingrowth from the aortic aspect, resulting in immobility of the occluder. A bioprosthetic valve was installed and the patient recovered uneventfully. The diagnosis and surgical management of this problem are discussed.