Twenty five patients with stage I and I1 diffuse aggressive non-Hodgkin's lymphoma of the Waldeyer's ring were reviewed. There were 19 patients with diffuse histiocytic, 4 diffuse lymphocytic poorly differentiated and 2 diffuse mixed lymphoma. Their median age was 51 years. There were 12 males and 13 females. Eight patients had stage I, and 17 had stage I1 disease. There was a significantly higher incidence of involvement of the left side of the Waldeyer's ring compared to the right (p =0.0251). Fifteen patients received radiotherapy alone, and ten had radiotherapy and chemotherapy. The median durations of follow-up were 42 (range 8-162) and 44 (range 8-97) months respectively. All patients had complete remission but 9 patients (36 per cent) subsequently had relapse of their lymphomas. Stomach was the commonest site of relapse (44 per cent). The disease free survival and overall survival at 5 years were 59 per cent and 57 per cent respectively. Higher relapse rate was observed in the radiotherapy alone group (60 per cent) as compared to the combined modality therapy group (0 per cent). Patients who received combined modality therapy had significantly superior 5 years disease free survival (100 per cent versus 32 per cent, p<O.Ol) and overall survival (81 per cent versus 40 per cent, p<O.O5). After radiotherapy alone, patients with stage I T disease appeared to have a high relapse rate than those with stage I disease (70 per cent versus 40 per cent) but the difference did not reach statistical significance due to small sample sizes. The histological subtypes did not appear to affect their prognosis. All patients with stage I and I1 diffuse aggressive non-Hodgkin's lymphoma of the Waldeyer's ring should have gastrointestinal barium studies at initial staging, and a prospective randomised study on these patients comparing radiotherapy alone and combined modality therapy should be performed.