A review of the in vivoand in vitrofluid dynamic performance of three bioprosthetic heart valves is presented. Data on Hancock porcine valves (standard models 242 aortic and 342 mitral and modified orifice model 250 aortic), Carpentier-Edwards porcine valves (model 2625 aortic and 6625 mitral), and the Ionescu-Shiley pericardial valve are reviewed. These valves were chosen because of their past or present popularity in clinical use and because of the variation in fluid dynamic performance reported by different investigators. The flow parameters that are reported include in vivoand in vitromean pressure drop, cardiac output or cardiac index, regurgitant volume, effective orifice area, and performance index. These data provide a framework for differentiation of normal and abnormal bioprosthetic valve function.