Postoperative chylous leak may result from thoracic duct injury during surgical procedures in the chest or neck and can be successfully treated with percutaneous embolization. We report the case of a child with persistent chylothorax and chyloperitoneum following multivisceral transplantation, which was performed due to unresectable inflammatory myofibroblastic tumor of the retroperitoneum. Intranodal lymphangiography was used to demonstrate the site of chylous leak from the lower segment of the thoracic duct and the leak resolved within days following percutaneous embolization of the thoracic duct.