We report a case of a pheochromocytoma that exclusively secretes dopamine among a blend of catecholamines. A 66-year-old female was referred to our hospital for further examination of right adrenal tumor. She had no symptoms and no episodes of hypertension. Abdominal CT scan showed a large mass, 9 x 8 x 6 cm, in the right adrenal region. Plasma and urinary catecholamine measurements were repeatedly performed and showed normal adrenaline and noradrenaline but elevated dopamine levels. We performed right adrenalectomy. The tumor was completely removed surgically and histological examinations revealed it to be a pheochromocytoma.