The authors have analyzed results of examination of 107 patients with infective endocarditis (IE) of the natural (IENV) and artificial valves (IEAV) of the heart. It was found that the revealed ultrasonic symptoms of IE were specific in 97.7% of patients with IENV and in 100% of patients with IEAV. The sensitivity of transthoracal echocardiography was 89.6% in patients with IENV and 65% in patients with IEAV. The intracardiac morphological alterations were found to coincide with the findings of echocardiography in 78.2% of patients with IENV and in 55%--with IEAV. The authors have elaborated an algorithm of the complex diagnostic examination of patients.