Effusive-constrictive pericarditis (ECP) is an increasingly recognized clinical syndrome. It has been best characterized in patients with tamponade who continue to have elevated intracardiac pressure after the removal of pericardial fluid. The disorder is due to pericardial inflammation causing constriction in conjunction with the presence of pericardial fluid under pressure. The etiology is diverse with similar causes to constrictive pericarditis and the condition is more prevalent with certain etiologies such as tuberculous pericarditis. The diagnosis is most accurately made using simultaneous intrapericardial and right atrial pressure measurements with pericardiocentesis, although non-invasive Doppler hemodynamic assessment can assess residual hemodynamic findings of constriction following pericardiocentesis. The clinical presentation has considerable overlap with other pericardial syndromes and as yet there are no biomarkers or non-invasive findings that can accurately predict the condition. Identifying patients with ECP therefore requires a certain index of clinical suspicion at the outset, and in practice, a proportion of patients may be identified once there is objective evidence for persistent atrial pressure elevation after pericardiocentesis. Although a significant number of patients will require pericardiectomy, a proportion of patients have a predominantly inflammatory and reversible pericardial reaction and may improve with the treatment of the underlying cause and the use of anti-inflammatory medications. Patients should therefore be observed for the improvement on these treatments for a period, whenever possible, before advocating pericardiectomy. Imaging modalities identifying ongoing pericardial inflammation such as contrast-enhanced magnetic resonance imaging or nuclear imaging may identify those subsets more likely to respond to medical therapies. Pericardiectomy, if necessary, requires removal of the visceral pericardium.