Treatment results were investigated in 113 previously untreated patients with clinical Stage I and II (Ann Arbor) non-Hodgkin's lymphoma of the head and neck. Fifty-six Waldeyer's ring, 34 other extranodal sites, and 23 cervical nodal lesions were included. The overall relapse-free survival at 5 years was 41%. Age and Ann Arbor stage influenced relapse-free survival. The results suggested that the tumor cell burden is a fundamental prognostic factor for patients with Waldeyer's ring disease and for patients with only cervical nodal disease. Abdominal relapse was most frequent, followed by generalized relapse. From 1981, patients were randomized in a clinical trial to receive either chemotherapy (cyclophosphamide, vincristine, and prednisone [CVP], five courses) or whole-abdominal irradiation (25 Gy/20 Fr) as an adjuvant therapy. Patients could not tolerate the whole-abdominal irradiation well. A significant improvement in survival has been obtained by adjuvant chemotherapy.