Xanthogranulomatous pyelonephritis (XGP) is a rare event in children without any predisposing factor like calculi, obstruction or vesicoureteral reflux. In this case we report a four-year-old girl who presented with a renal mass, hematuria, flank pain, anemia and thrombocytopenia-these signs and symptoms misled us to Wilms tumor. Thrombocytopenia which is a strange event in XGP resolved after nephrectomy. Normal contra lateral kidney was infected four months after right nephrectomy. This suggests that these patients should be under strict surveillance and antibiotic prophylaxis as they are a high-risk group for urinary tract infection, and thrombocytopenia should be considered as a laboratory test finding in XGP.