Infective endocarditis occurs in 4% of prosthetic valve carriers. The infection is related to both the injured endocardium and circulating microorganisms. Early prosthetic endocarditis, occurring in the first 12 months after valvular surgery is mainly caused by staphylococci, and late prosthetic endocarditis has a similar etiology as native valve endocarditis. Clinical manifestations of early cases are due to both bacteremia and prosthetic malfunction. In late cases the clinical picture is similar to native valve disease. Mortality in prosthetic endocarditis remains high, especially in early cases, despite combined medical and surgical treatment.