OBJECTIVE The objective of this work is to investigate the role of radiation therapy in the treatment of primary tracheal carcinoma. METHODS From 1963 to 1993, 106 patients presenting with a tracheal carcinoma received a radiation course as part of their treatment in three institutions. Eighty-four patients were treated with megavoltage radiation only, receiving doses ranging from 30 to 70 Gy, with a median dose of 56 Gy. Five patients received high-dose-rate (HDR) brachytherapy, five patients underwent a surgical procedure, and eight received chemotherapy. RESULTS With a mean follow-up of 141 months, the overall 1-, 2-, and 5-year survival rates are 46%, 21%, and 8%, respectively. Prognostic factors included tumor size (less than 3 cm), performance status, and total radiation dose: the 5-year survival rate dropped from 12% for patients receiving doses greater than 56 Gy to 5% for lower doses. Performance status and radiation doses are the only independent significant factors in multivariate analysis; these results must however be analyzed with precaution in this retrospective study. CONCLUSIONS Radiation is a good alternative to surgery for primary tracheal cancer. A review of the literature and our current results allow us to recommend a radiation dose greater than 60 Gy for primary irradiation. Collaborative studies are warranted to (1) determine the optimal radiation dose for definitive irradiation, (2) define the potential role of radiation after complete and partial surgery, (3) determine the role and optimal treatment scheme for HDR brachytherapy, (4) describe and record the late effects, (5) establish the potential benefit of chemoradiation.