We experienced a case of ventilation difficulty after intubation due to tracheal diverticulum caused by radical surgery for esophageal atresia/tracheoesophageal fistula repair. The patient was a sevenmonth-old male infant. Esophageal stricture was found after radical surgery for type C esophageal atresia, so an esophageal balloon dilatation under general anesthesia was scheduled. Tracheal intubation was easily accomplished after general anesthesia was induced, but audible breathing and chest movements were not detected after manual ventilation, so extubation was performed and mask ventilation initiated. Similar ventilation difficulties occurred after re-intubation, but ventilation became possible with a shallow intubation. Upon further investigation using bronchoscopy, it was determined that the ventilation difficulty had been caused by the tip of the tracheal tube straying into a posterior tracheal wall diverticulum. Tracheal diverticulum, which is a complication of radical surgery for esophageal atresia/tracheoesophageal fistula repair, should be considered as a potential cause of ventilation difficulties following intubation.