Sixty-four patients (37 stage I and 27 stage II) with low grade non-Hodgkin's lymphoma were treated by surgical excision alone (two patients) or with radiotherapy (53 patients), chemotherapy (five patients) or both (four patients). Actuarial survival was 80.7% at 5 years and 77.9% at 10 years. Actuarial recurrence-free survival at 10 years was 49.4% for stage I and 38.0% for stage II patients. Local control was achieved in 52 out of 56 (93%) patients treated with a radiation dose of 30 Gy or greater. There was no advantage for extended compared with involved, field irradiation. A multivariate analysis identified age, sex, stage and disease site as independent prognostic variables for survival.