Paragangliomas are rare neuroendocrine tumors that arise from sympathetic and parasympathetic paraganglia. In children, most of them are functional tumors. Presenting symptoms such as sustained or paroxysmal elevations in blood pressure, headache, sweating, and palpitations are related to catecholamine hypersecretion. A previously healthy 8-year-old boy presented with marked proteinuria, hypertension, and heart murmur. Imaging revealed an 81×43×45 mm sized solid mass extending from right retroaortic area to left suprarenal region. Measurements of catecholamines suggested the diagnosis of paraganglioma. Pathologic examination confirmed the diagnosis. Complete tumor resection was performed. Proteinuria, hypertension, and cardiac signs resolved after surgery. Proteinuria has been described as a rare manifestation of paragangliomas in adult patients. This is the first case of a paraganglioma presenting with massive proteinuria in a child.