Infective endocarditis is caused by the infection of an amorphous mass of platelets and fibrin (the so-called nonbacterial thrombotic endocarditis) which involves a damaged endothelial surface of the heart. Several pathogenetic mechanisms (hemodynamic, immunological, microbiological, etc.) are needed for the development of endocarditis. We review some of these mechanisms, as well as possible changes in etiopathogenesis of this disease that have recently occurred.