Immediate and long-term prognosis of patients with prosthetic valves critically depends on prevention, rapid diagnosis, and optimal treatment of complications. This review describes the current practice in management of prosthetic dysfunction and discusses unresolved or controversial issues such as: what is the optimal anticoagulation regimen in both mechanical and bioprosthetic heart valves? Is thrombolysis superior to surgery in thrombotic valve obstruction? Is valve replacement superior to conservative therapy for prosthetic valve endocarditis? In addition, recently obtained data relating to the incidence of early and late mortality, thromboembolism, anticoagulation-related hemorrhage, valve thrombosis, hemolysis, paravalvular leakage, and the necessity and risk of reoperation are presented.