In 1980, on the basis of fundamental and clinical data, a protocol was developed at the Institut Gustave-Roussy, alternating eight monthly courses of chemotherapy (CHVP) and two or three radiotherapy sequences (15 Gy in 6 fractions of 10 days, each), to treat non-Hodgkin's lymphomas of unfavourable histologies, mainly stage II, presenting bulky tumours. Systemic, haematological and digestive tolerances were satisfactory. For 19 previously untreated stage II patients, overall survival and relapse-free survival after 30 months were 85 and 65%, respectively. Three of the relapses were observed in patients who did not receive the alternating schedule in an optimal way; this suggests that these results can be further improved.