One hundred and fifty-seven previously untreated stage B or C B-CLL patients were randomized to treatment with either chlorambucil + prednisolone (CLBP) 5 days every 4 weeks or CHOP every 4 weeks. Significantly more patients achieved complete remission on CHOP, but duration of response and survival were equal in the two regimens. Non-responders on CLBP were switched to CHOP, so that finally most patients received nearly the same amount and quality of treatment, which possibly explains the lack of difference in survival. However, compared to previous studies, the study-designed intensive chemotherapy seems to prolong survival for patients with advanced disease, especially those in stage C.