Barrett's esophagus, a premalignant condition, is recognized as stratified squamous epithelium of the esophagus substituted by columnar epithelium. The risk factors for development of Barrett's esophagus include frequent gastroesophageal reflux, esophageal stricture, male sex and mental retardation, but there is no report of Barrett's esophagus in children with de Lange syndrome. We report a 7-year-old boy who was diagnosed as de Lange syndrome shortly after birth and had gastroesophageal reflux since early infancy. Upper gastrointestinal endoscopic examination revealed a cauliflower-like mass and a pink-red velvety mass over the lower third of the esophagus. Biopsy showed goblet cells metaplasia, confirming Barrett's esophagus. We suggest surveillance of Barrett's esophagus could be done ahead of schedule in children with long-standing gastroesophageal reflux or with de Lange syndrome.