A 59-year-old woman who was diagnosed with malignant pheochromocytoma underwent 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). She had undergone left adrenalectomy for pheochromocytoma 4 years previously. Recent multiple metastatic pulmonary nodules were noted on the chest X-ray. After treatment with 131I-metaiodobenzylguanidine (131I-MIBG) with 7.4 GBq, post-therapy 131I-MIBG scintigraphy depicted multiple distant metastases including lung, liver, abdominal para-aortic and mesenteric lymph nodes. 18F-FDG PET/CT also depicted multiple metastases in lung, liver, and abdominal para-aortic lymph nodes, but some lesions were not shown. In this case, 131I-MIBG scintigraphy found additional lesions in metastatic malignant pheochromocytoma.