Extrarenal Wilms tumors (ERWT) are extremely rare with only isolated case reports in the pediatric literature. As there are no specific radiological findings suggesting ERWT, it is difficult to diagnose ERWT accuaretely without pathological description. We present two cases who presented with large retroperitoneal masses. Wilms tumor was not considered in differential diagnosis as the masses were located outside the kidney. An emphasize on ERWT’s clinical and surgical findings and differential diagnosis were made in this report.