Two years and eight months after having had hyperalimentation during an infection, a 4-year-old boy was readmitted to the hospital with a viral syndrome. A chest X-ray film showed calcification over the right heart. After treatment of the viral problem, the boy was readmitted for evaluation of the calcifications. Percutaneous angiography demonstrated right atrial filling defects in the areas of calcification. The inferior vena caval pressures were normal. An echocardiogram showed a normal left atrium and mitral valve but did not reveal the masses within the right atrium. An electrocardiogram showed mild right ventricular hypertrophy. The patient subsequently underwent resection of 75% of the right atrial wall, which was involved with the growth, and this was reconstructed by using pericardium. The final pathological report described marked endocardial fibrosis infiltrated by chronic inflammatory cells consistent with organized mural thrombus. This case represents a complication of central venous catheterization secondary to traumatization of the endocardium by constant action of the heart against an indwelling catheter.