The pericardium serves many important functions but is not essential for life. Pericardial heart disease comprises only pericarditis and its complications, tamponade and constriction, and congenital lesions. However, the pericardium is affected by virtually every category of disease. Thus the critical care physician is likely to encounter the patient with pericardial disease in a variety of settings, either as an isolated phenomenon or as a complication of a variety of systemic disorders, trauma, or certain drugs. Despite exhaustive etiological lists, the cause of pericardial heart disease is often never identified. This article reviews the diagnosis and management of acute and chronic pericarditis with an emphasis on those areas of greatest interest to the intensivist.