Pheochromocytomas are tumors arising from chromaffin cells that synthesize, store, metabolize and usually secrete catecholamines. Majority arise from the adrenal glands but there are cases of extra-adrenal pheochromocytoma that develop in the paraganglionic chromaffin tissue of the sympathetic nervous system anywhere from the base of the brain to the urinary bladder. they are usually benign but 10 percent of cases may be malignant. Tumor exension to the renal vein or inferior vena cava is rare. We report a case of a pediatric patient with three years history of dizziness with associated headache, weakness, tremors, palpitations and hypertension with CT scan and MRI findings of a renal mass t/c renal cell carcinoma with renal vein and inferior vena cava thrombus. Final histopathologic examination revealed pheochromocytoma.