Eighty-five patients with advanced squamous cell carcinoma of the head and neck were treated with twice-a-day fractionation schedules between April 1972 and December 1980. Two types of treatment were distinguished: hyperfractionation, by which 65 patients (Group I) were treated at a weekly dose rate of 1100 to 1200 rad (10 fractions of 110 to 120 rad) in 5 to 6 1/2 weeks for either advanced primary disease (Group 1A) and/or advanced neck metastases (Group IB); and accelerated treatment, used to treat 20 patients (Group 2) who had fast-growing and usually massive neck nodes, at a weekly dose rate of 1300 to 1500 rad in 7 to 10 fractions, to a total dose of 6100 to 8000 rad in 4 to 6 weeks. The radiation portals for patients in Group 2 excluded the mucosa of mouth and throat for part of the treatment. The local control rate at 1 year in Groups 1A and 1B was 41 and 54%, respectively; the incidence of complications was 17%, 5% of them fatal. The local control rate in Group 2 was 80%. Seven patients in this group underwent a neck dissection 6 to 8 weeks following irradiation. Four specimens were negative for tumor. In two, only necrotic tumor cells were identified, and in one specimen morphologically intact tumor cells were seen. There were no fatal complications.