Patients with squamous cell carcinoma of the esophagus (124) were randomized for inclusion in a prospective trial of preoperative irradiation. Sixty-seven patients were randomly selected to receive 4000 rads of cobalt radiation for 8 days prior to operation; 57 patients were operated upon without receiving radiation therapy. No significant differences were noted between the 2 groups with regard to age, sex, tumor site, experience of the surgeon, method of approach or surgical technique. Of the 62 irradiated patients, 14 died during operation, compared with 11 of the 47 nonirradiated patients, the difference between the 2 groups not being statistically significant. Irradiation was associated with a higher mortality for lesions in the middle 1/3 of the esophagus, 11 of 29 vs. 4 of 19, but again, the difference was not significant. In the irradiated patients, the 5-yr actuarial postoperative survival rate was 9.5 vs. 11.5% for the nonirradiated patients. Preoperative radiation therapy does not produce a statistically significant short-term or long-term benefit in the management of squamous cell carcinoma of the esophagus.