Common causes of acquired tracheoesophageal (T-E) fistula are blunt trauma on the neck or chest, malignancy, long-term mechanical ventilation, and post-intubation injury. Most of the cases are fatal due to severe respiratory infection. We experienced two cases of post-intubation T-E fistula in patients with a history of tracheostomy that developed earlier than usual. One case was caused by excessive cuff pressure and the other by avulsion injury during endotracheal intubation. We can get instructions from these cases that how to prevent T-E fistula because it is hard to treat and causes severe outcomes.