Xanthogranulomatous pyelonephritis is a chronic renal inflammation characterized by destruction and replacement of its parenchyma with granulomatous tissue. This uncommon condition is rare in children. We report on a 5-month-old male infant with a left renal and hepatic mass detected by ultrasound. The case was preoperatively misdiagnosed as Wilms' tumor and total nephrectomy and biopsy from liver lesion were performed. The subsequent histopathological findings confirmed the diagnosis of xanthogranulomatous pyelonephritis for renal and liver lesions. Increasing awareness of this disease should lead to the diagnosis being suspected preoperatively even if it is with unconnected tissue lesions. UROLOGY 78: 189-191, 2011. (C) 2011 Elsevier Inc.