Wilms' tumor (WT) is one of the solid tumor that affects children. It involves the kidney and may extend to the lungs and liver. WT conquers the adjacent blood vessels such as renal veins and inferior vena cava (IVC); its extension to IVC and right-sided heart chambers is unusual. Furthermore, when the tumor extends to heart chambers, its surgical management becomes challenging and demands multidisciplinary medical and surgical specialties including pediatric cardiac surgery. In this report, we discuss the surgical management and perioperative treatment of two unusual cases of WT with IVC and intracardiac extension.