Unlike other extraintestinal inflammatory manifestations of ulcerative colitis, cardiac involvement is infrequently reported and inadequately characterized, with only 9 previously reported cases of pericardial tamponade associated with inflammatory bowel disease. A 32 year old male with ulcerative colitis, treated with orally administered mesalamine for ten years, developed chronic pericarditis. Extensive clinical and laboratory evaluation failed to find any cause of the pericarditis other than the ulcerative colitis. Although the pericarditis remitted with indomethacin therapy, this medicine had to be discontinued because of a reactivation of ulcerative colitis attributed to this nosteroidal antiinflammatory drug (NSAID). The pericarditis then responded well to high-dose corticosteroid therapy, but the patient represented with chest pain, dyspnea, tachypnea, and engorged neck veins after tapering the corticosteroid therapy. Angiography revealed near equalization of end diastolic pressures in both ventricles, a finding consistent with pericardial tamponade. The patient underwent subtotal pericardiectomy. Thoracotomy revealed a thickened pericardial wall and a large pericardial effusion. The patient's symptoms resolved postpericardiectomy. This case extends the clinical spectrum of pericarditis associated with ulcerative colitis, by describing a case of pericarditis that was chronic, refractory to maintenance medical therapy, caused pericardial tamponade, and was successfully treated by pericardiectomy.