Xanthogranulomatous pyelonephritis is an unusual type of the kidney infection which is characterized by infiltration of mononuclear inflammatory cells and lipid laden macrophages ( foam cells). It is manifested by a firm, lobulated and yellowish kidney mass which is difficult to differentiate from renal cell carcinoma grossly. Six out of 1000 cases of cryonic pyelonephritis which are treated surgically , are turned out to be diagnosed as a xanthogranulomatous pyelonephritis. The number of diagnosed cases are increasing in recent years. This may be due to improvement in radiological diagnostic methods and characteristic clinical manifestation. In the study, we report a case of xanthogranulomatous pyelonephritis in a 5 year old boy with a kidney mass, recurrent urinary tract infection and nonfunctional kidney which is diagnosed clinically and confirmed histopathologically.