Ten children (4.6%) among a cohort of 219 with Kawasaki disease (KD) had their onset with severe abdominal complaints. Incomplete KD presentation at the time of acute abdomen was present in nine of 10 patients. Acute abdominal pain and distension, vomiting, hepatomegaly, and jaundice were the most common symptoms at onset. Hematemesis was present in one; toxic shock syndrome requiring care in the intensive care unit occurred in four. Five patients had laparotomy, three had percutaneous transhepatic biliary drainage, and one had a gastrointestinal endoscopy. Postoperative diagnosis was gallbladder hydrops with cholestasis in five, paralytic ileus in three, appendicular vasculitis in one, and hemorrhagic duodenitis in one. All patients completely recovered, but 50% developed coronary aneurysms despite early intravenous gammaglobulin treatment. Acute surgical abdomen can be the presenting manifestation of KD. In older children with fever, rash, and acute abdominal pain or hematemesis, KD should be considered in the differential diagnosis.