This study aimed to investigate the clinical characteristics, diagnostic approaches, treatment strategies, and prognosis of Kawasaki disease (KD) complicated by duodenal bleeding, in order to enhance awareness of this rare but potentially life-threatening condition. We retrospectively analyzed a case of a child with KD admitted to our hospital due to duodenal bleeding, and included three additional cases identified through a literature review. Clinical data were systematically compared, covering demographic features, manifestations, laboratory findings, imaging and endoscopic results, interventions, and outcomes. All four patients were male, aged 2.5–11 years, and presented with typical KD, atypical KD, or Kawasaki disease shock syndrome (KDSS). Initial symptoms included fever, rash, and conjunctival congestion, followed by gastrointestinal bleeding such as melena, hematemesis, or hemorrhagic shock. Endoscopy confirmed duodenal bulb ulcer or perforation as the bleeding source. Some patients showed non-response to intravenous immunoglobulin (IVIG) or developed severe cardiovascular complications, including coronary artery aneurysm. Management consisted of IVIG therapy, antiplatelet or anticoagulant agents, proton pump inhibitors, endoscopic hemostasis, and surgical repair when necessary. Most children achieved favorable outcomes, with stabilization of cardiac involvement and no further progression. In conclusion, duodenal bleeding is an uncommon but serious complication of KD, particularly in cases associated with IVIG resistance, KDSS, or severe systemic inflammation. Early recognition, timely gastrointestinal evaluation, and active hemostatic and supportive measures are crucial for improving prognosis.