Although most valve operations performed annually address lesions of the aortic or mitral valves, the frequency of pulmonary valve replacement (PVR) is increasing because most patients with congenital heart disease are surviving into the adult years. The vast majority of patients, especially children that require PVR, obtain a tissue valve because of the relative good durability and the lack of a need for anticoagulation. Because the need for repeat operation is inevitable for most patients, and the population of adults with congenital heart disease continues to grow, there are increasing situations in which a mechanical pulmonary prosthesis may be appropriate. Most patients being considered for mechanical PVR have a congenital diagnosis and require multi-valve procedures, and quality of life and need for repeat operation(s) are major issues. Mechanical valves are durable but require anticoagulation, which carries its own inherent set of risks. There are conflicting reports regarding the late outcome of mechanical PVR. There are few reports that indicate that, in the pulmonary position, bileaflet valves are at higher risk for complications compared with monodisc valves; however, the majority of these patients were not anticoagulated with warfarin, but simply maintained on aspirin. There is a growing body of literature documenting low rates of thrombosis or pulmonary prosthesis dysfunction when proper anticoagulation and monitoring are applied.