A group of 20 patients with ventriculoatrial shunts placed as surgical treatment for hydrocephalus were evaluated for cardiac lesions, particularly of the tricuspid valve. Patients with histories of septic or thromboembolic events were excluded. In each patient a clinical history, complete physical examination, electrocardiogram, chest x-ray film and M-mode, two-dimensional and pulsed continuous wave and color-coded Doppler echocardiography were performed. Eight patients were found to have cardiac abnormalities including tricuspid valve insufficiency, tricuspid stenosis and insufficiency, and the catheter passing through the foramen ovale into the left atrium. These findings demonstrate that tricuspid valvular lesions are frequent in patients with ventriculoatrial shunts, and that periodic echocardiographic evaluation should be performed routinely.