The development of an adenocarcinoma in a reconstructed tube after subtotal esophagectomy for esophagus squamous cell carcinoma (ESCC) is uncommon and has been reported in articles from the Japanese medical community. We report three cases of patients who had this clinical presentation. We suggest an approach to postoperative management of ESCC to identify early tumors in gastric tubes and to allow endoscopic or surgical curative treatment.