Patients with prostheses of the cardiac valve are, related to the total population, only a small part. But their number permanently increases. Alone in our clinic since 1973 3,250 patients have been provided with artificial cardiac valves. Thus more and more physicians are confronted with the problems of these patients. The long-term results after replacement of the cardiac valves are very essentially influenced by the prevention and well-timed recognition of complications, respectively. For this reason the medicamentous therapy is demonstrated on the basis of own experiences and modern literature. It is clearly pointed out that after replacement of the cardiac valve a permanent cardiologic control is necessary. In detail is reported on the therapy of cardiac insufficiency including disturbances of the cardiac rhythm, on the prophylaxis of thromboembolism as well as on the prophylaxis of endocarditis.