The Dieulafoy's lesion is a rare cause of recurrent massive gastrointestinal bleeding in children. The bleeding results from an abnormally large submucosal artery that protrudes through a small mucosal defect. The lesion is commonly found on proximal stomach. Surgical intervention was believed to be the best treatment in the past, but recent advancement in endoscopy has made effective hemostasis possible. We report a case of a 9-year-old boy with underlying mycoplasma pneumonia with effusion who presented with massive upper gastrointestinal bleeding. Bleeding was controlled with endoscopic treatment by epinephrine and ethanol injection and the patient was successfully treated.