Abstract A patient with intrapericardial pheochromocytoma is described, and the literature on this subject is reviewed. Iodine 131-labeled metaiodobenzylguanidine scintigraphy was superior to computed tomography in localizing the tumor. This newly introduced method is safe, specific, noninvasive, and may prove to be the method of choice for localizing pheochromocytomas. The patient was prepared for surgery with alpha- and beta-adrenoceptor blocking agents. The tumor was markedly adherent to the posterior wall of the left and right atria. Cardiopulmonary bypass was used to allow excision of the tumor. Hemostasis was attained with difficulty due to marked vascularity of the tumor.