A clinical and echocardiographic study was carried out to evaluate the systolic and diastolic functions of the left ventricle in both Rheumatoid Arthritis and Juvenile Rheumatoid Arthritis patients without evidence of cardiac disease. Diastolic dysfunction was found in RA patients more than in JRA patients, particularly in patients with long disease duration or active disease. This raises the importance of performing echocardiography in both RA and JRA patients even if they are free from cardiac symptoms.