Cardiac tamponade is a rare complication of juvenile rheumatoid arthritis. Three cases seen in the last two years at the Children's Hospital of Philadelphia are reported and compared to four previously reported cases. All three children had systemic-type juvenile rheumatoid arthritis with tachypnea, shortness of breath, and chest pain. Cardiac signs in these children included decreased heart sounds, pericardial friction rub, jugular venous distention, and pulsus paradoxus greater than 12 mm Hg. Roentgenograms of the chest showed cardiomegaly with bilateral pleural effusions. Electrocardiograms showed sinus tachycardia and nonspecific ST-T wave changes. Echocardiograms demonstrated pericardial effusions in all subjects and poor ventricular movements in one child. All three children were treated with short-acting anti-inflammatory drugs and/or prednisone. Pericardiocentesis was performed in two cases. There was no significant morbidity after a mean follow-up of two years.