Prosthetic valve replacement replaces a heart disease with another one. There is no ideal prosthetic valve. All prostheses need to be followed by caution and treatment depends on the type of the prosthesis. Mechanical prostheses add anticoagulant drugs to patient’s life and degeneration of bioprostheses requires reoperation. Prosthesis dysfunction includes a group of pathological processes like thrombosis, thromboemboli, valvular or paravalvular regurgitation, patient-prosthesis mismatch, infective endocarditis and bioprosthesis degeneration. Correct diagnosis and treatment of these problems will decrease the mortality and morbidity due to prosthetic valve disease