The indications for pericardiectomy as well as the causal factors have changed in recent years. Sixty-eight patients operated on at the UCLA Medical Center between 1955 and 1982 have been described. There were 37 male patients and 31 female patients. The indication for operation was acute pericarditis in 37 patients, of whom 31 had recurrent effusion, and chronic constrictive pericarditis in 31 patients, of whom 8 were calcific. The most common cause of pericardial disease was tumor (20 patients), followed by idiopathic (13 patients), uremic (7 patients), viral (7 patients), tuberculous (6 patients), rheumatologic (6 patients), and miscellaneous (9 patients) causes. In most patients, pericardiectomy was performed through a left anterolateral thoracotomy without cardiopulmonary bypass. We recommend wide excision of the anterior pericardium (phrenic nerve to phrenic nerve) for effusive pericarditis. For chronic constrictive disease, we advocate a more extensive resection that includes the anterior as well as the posterior pericardium, thus freeing the left and right ventricles. Excellent long-term results were obtained with pericardiectomy in 90 percent of the patients who survived the operation.