We describe a patient with labile hypertension and elevated metanephrines who underwent 123Iodine metaiodobenzylguanidine (MIBG) for the detection of a possible paraganglioma. The scan revealed markedly abnormal diffusely increased activity in the right renal parenchyma. A CT angiogram showed severe renal artery stenosis of an atrophic-appearing right kidney and delayed enhancement of the right kidney, consistent with renal dysfunction due to renal artery stenosis.