Primitive neuro-ectodermal tumors (PNETs) are seenmostly at central nervous system. Peripheral localizationsare rare. PNETs are belong to Ewing sarcoma family. Ewingsarcoma has two subtypes as originated from bonesor from another organ. Renal PNET is a very rare tumor.Peripherally localized PNETs originated from kidney, usuallyfound at young men, and have poor prognosis withaggressive behavior. A 28-year-old man referred to ourclinic with left flank pain and gross hematuria. Radiologicalinvestigations yielded gross renal mass compatiblewith malignancy. Radical nephrectomy was performed.Histopathological diagnosis was PNET/Ewing sarcomawith findings of large and hyperchromatous nuclei, narrowcytoplasms, spindle shaped cells- but mostly rosette formation-and strong straining with CD99. Chemotherapywas given to the patient. At the end of the chemotherapy,there no recurrence was detected by radiological investigations.J Clin Exp Invest 2012; 3(1): 127-129