Although there has been a recent trend toward early operative treatment of uremic pericardial effusions unresponsive to intensified dialysis, this approach may be unnecessarily aggressive. Review of 787 patients in our chronic dialysis program since 1969 has shown 54 patients (6.9 percent) to have developed 56 episodes of large pericardial effusion. All were managed by increasing the frequency of dialysis. If the effusion failed to diminish or if life-threatening signs of tamponade developed, pericardiocentesis was performed. In 63 percent (35/56) the effusion resolved with increased dialysis. In 37 percent (21/56), pericardiocentesis was performed, with 57 percent (12/21) requiring only one aspiration. During a mean follow-up of 34 months (2 to 100 months) only 5.5 percent (3/54) have undergone operation: one partial pericardiectomy incidental to pulmonary decortication and two pericardiectomies for late (3 months and 5 months, respectively) constriction. There were five complications of pericardiocentesis: one pneumothorax, one pneumoperitoneum, one costochondritis, and two myocardial punctures without sequelae. The one death related to pericardial effusion in this series occurred in a home-dialysis patient who arrived in the emergency room moribund. Our experience suggests that the great majority of uremic pericardial effusions can be effectively controlled with simple needle aspiration by experienced personnel and that pericardial resection is usually not necessary.