In 1980, based on experimental and clinical data, a protocol was developed at the Institut Gustave-Roussy (IGR), alternating eight monthly courses of chemotherapy (CHVP) and two, then three, radiotherapy sequences (15 Gy in 6 fractions and 10 days to the initially involved areas), for early stage unfavourable histology non-Hodgkin lymphomas (NHL). The results are updated for 55 selected patients presenting with bulky stage I and II NHL, intermediate and high grade according to the Working Formulation. Five-year overall survival rate was 69% and freedom from progression was 68%. Early haematologic and digestive tolerance was satisfactory, probably because a 10-15-day interval was respected between chemotherapy and radiotherapy and vice versa. No late toxicity was detected in 39 patients who presented with head and neck localizations; xerostomia was found to be only mild and transient. All patients given mediastinal irradiation experienced radiological mediastinitis, but functional impairment was usually moderate. One of the 4 patients who received 3 x 15 Gy radiotherapy courses to part of the abdomen, died of small bowel obstruction and perforation. The study demonstrated the feasibility of an alternated schedule of chemotherapy and radiotherapy, with satisfactory results in terms of long-term survival. However, the few late complications which were detected after irradiation of the abdomen or of the thorax led to an alteration of the initial scheme when these volumes are to be treated.