The Patterns of Care Study, begun in 1973, carried out its second outcome survey from December 1978 through April 1979. The review of patients with epidermoid carcinomas of the anterior two-thirds of tongue and floor of mouth included patients treated between January 1973 and June 1975 so that a minimum follow-up period of 2 years was evaluable. Records of 434 patients from 96 facilities were available for analysis, although not every patient could be evaluated for every variable. Almost three-fourths (320) were treated with radiation alone. In these data, four patient and disease characteristics were strongly related to recurrence rates including stage at presentation, deep ulceration, deep infiltration, and age. Treatment variables significantly affecting recurrence included use of interstitial therapy in Stages I and II, use of surgery in Stages III and IV, and a facility's best equipment.