A child had consumption coagulopathy associated with Wilms' tumor and extensive thrombosis of the renal veins, extending to the inferior vena cava, the intrahepatic and portal veins, and the right atrium. There was a history of abdominal pain and vomiting with findings of altered consciousness, tachycardia, hepatomegaly, and oliguria. The rapid onset of consumption coagulopathy contributed to death two days after the tumor was first discovered.