Objectives: Patients with esophageal cancer and a malignant tracheoesophageal fistula(TEF)have an extremely poor prognosis, with or without treatment. However, the presence of a TEF has historically been considered a relative contraindication to radiation therapy. Methods: To determine the appropriate treatmement(use of radiation therapy)for patients with esophageal cancer and malignant TEF, a review was performed of all such cases, obeserved at Asan Medical Center between 1989 and 1993. Results: 1) Six patients with malignant TEF were seen in total 130 esophageal cancer patients, so the incidence was 4.6%. 2) All of the patients were male, had squamous cell histologies. 3) Dysphagia as initial presenting symptom was a chief complaint in all six patients. 4) The number of TEF formation was one in five of six patients, two in the rest. 5) Three TEFs were developed during radiotherapy, two of them stopped radiation therapy, and one patient continued to treat with hyperfractionated radiation and cured. 6) The median survival length was 33(3-60) weeks after initial tumor diagnosis and 16(2-39) weeks after the first TEF occurred. The duration between initial tumor diagnosis and TEF formation was 17.6(0.6-22) weeks. 7) As a pllliative aim, gastrostomy was done in two patients, jejunostomy in one patient, and stent insertion in the other two patients. Associated symptoms with TEF were markedly improved after stent insertion. 8) The cause of death was sepsis as a resulf of aspiration pnenumonia and lung abscess in five of six patients, and advanced esophageal cancer with lung metastasis in the rest. Conclusion: Early detection and proper management were essential in malignant TEF and esophageal cancer. Stent insertion was good palliation. Radiation therapy might be initiated or continued in the presence of a TEF, and eventual resolution of the fistula might occur. Prospective randomized trials are necessary to define the role of radiation treatment, and further attempts to improve the malignt TEF are required.