We have reviewed the records of 76 patients with Stage I or II extranodal non-Hodgkin's lymphoma who were referred to the Division of Radiation Oncology, Mallinckrodt Institute of Radiology, during the years 1964 through 1974. The histologic slides were reviewed in the 67 cases in which they were available. Forty-three percent of Ann Arbor Stage I and II patients relapsed after primary radiation treatment.Seventy-three percent of these failed in sites distant from the irradiated volume. Failures in the treated volume were infrequent (7%) except in those patients presenting with primary lesions of the brain (4/5). Those patients presenting with lesions of Waldeyer's ring experienced a decrease in survival with increasing tumor size. Because of the high rate of failure in distant sites with tumors in the lingual and palatine tonsils, we are recommending the study of adjuvant chemotherapy in these cases, after primary radiation treatment.