BACKGROUND Effusive-constrictive pericarditis is an uncommon pericardial syndrome characterized by concomitant tamponade, caused by tense pericardial effusion, and constriction, caused by the visceral pericardium. We conducted a prospective study of its clinical evolution and management. METHODS From 1986 through 2001, all patients with effusive-constrictive pericarditis were prospectively evaluated. Combined pericardiocentesis and cardiac catheterization were performed in all patients, and pericardiectomy was performed in those with persistent constriction. Follow-up ranged from 1 month to 15 years (median, 7 years). RESULTS A total of 1184 patients with pericarditis were evaluated, 218 of whom had tamponade. Of these 218, 190 underwent combined pericardiocentesis and catheterization. Fifteen of these patients had effusive-constrictive pericarditis and were included in the study. All patients presented with clinical tamponade; however, concomitant constriction was recognized in only seven patients. At catheterization, all patients had elevated intrapericardial pressure (median, 12 mm Hg; interquartile range, 7 to 18) and elevated right atrial and end-diastolic right and left ventricular pressures. After pericardiocentesis, the intrapericardial pressure decreased (median value, -5 mm Hg; interquartile range, -5 to 0), whereas right atrial and end-diastolic right and left ventricular pressures, although slightly reduced, remained elevated, with a dip-plateau morphology. The causes were diverse, and death was mainly related to the underlying disease. Pericardiectomy was required in seven patients, all of whom had involvement of the visceral pericardium. Three patients had spontaneous resolution. CONCLUSIONS Effusive-constrictive pericarditis is an uncommon pericardial syndrome that may be missed in some patients who present with tamponade. Although evolution to persistent constriction is frequent, idiopathic cases may resolve spontaneously. In our opinion, extensive epicardiectomy is the procedure of choice in patients requiring surgery.