Echocardiography was performed in 50 patients in chronic renal failure with symptoms suggestive of possible cardiac involvement. Pericardial effusions were detected in 33 and pericardial thickening in 22. In five patients solid material, probably fibrinous, was seen adherent to the parietal or visceral pericardium. The left ventricle was dilated in 18 patients and showed definitely impaired contractility in 16. The left ventricular (LV) posterior wall was abnormally thick in 19 patients. In two, the ventricular septum was more than 1.3 times as thick as the LV posterior wall. Other echocardiographic findings included calcification in the mitral annulus region, mitral valve vegetations, and thickened chordae tendineae. Echocardiography has proved to be of great help in the assessment of symptomatic patients with chronic renal failure not only in diagnosing the presence and extent of pericardial effusion and thickening, but also in detecting impaired myocardial contractility, calcification in the posterior mitral annulus region, and vegetations of bacterial endocarditis.