SUMMARY We report the case of a 2 years old male infant, with a history of recurrent urinary tract infection and high temperature during several days. On admission he had a temperature of 38.5 ° C and a soft, non-tender, well-defined 4 cm mass in the left lumbar region. Preoperative tests suggested the presence of a left renal tumor for which a laparotomy was performed with the following finding; left kidney with a smooth capsule with small yellow hard nodules adhered to its surface along the extension of the outer edge. A left nephrectomy was performed. He had an uneventful postoperative period and was discharged in good general condition. The pathological study reported a Xanthogranulomatous Pylonephritis