Recurrence at the primary site is an important cause of morbidity and mortality in head and neck cancer. In patients with stages III and IV disease treated surgically at Memorial Sloan-Kettering Cancer Center between 1960 and 1970, cancer recurred at the primary site in 39% even when the margins had been deemed satisfactory, and in 73% when the margins were unsatisfactory. Between 1975 and 1980, we treated 114 previously untreated patients with stages III and IV epidermoid carcinoma of the oral cavity, oropharynx, hypopharynx, or larynx with a combination of surgery and postoperative radiation therapy. Twenty-seven patients also received preoperative chemotherapy. One hundred seven patients were evaluable for disease control at the primary site by the combined treatment. Cancer recurred at the primary site in 6 patients, including 2% of 47 patients whose surgical margins had been satisfactory and 10.5% of 60 patients whose surgical margins had been unsatisfactory. Of the latter, recurrence was seen in 5% of the 25 patients whose margins were less than 5 mm but were microscopically uninvolved, and in 15% of the 35 patients whose margins were microscopically involved by cancer. Comparison of these data with our historical control group suggests a decrease in the failure rate at the primary site with multimodality treatment. However, it still appears important to secure microscopically negative margins for the best results.