The quick reduction of differentiated myeloma cells by VAD chemotherapy (vincristine, adriamycin, dexamethasone) causes, according to the investigation by Bell et al., the acceleration of the proliferation of myeloma stem cells. In 1990 Bell demonstrated that this proliferation could be stopped by administering 500 mg of cyclophosphamide in 1-week intervals. We therefore modified the classical VAD scheme to the following "C-VAD" scheme:vincristine 0.5 mg/day in continuous infusion on the first to the 4th day, adriamycin 9 mg/m2/day in continual infusion on the 1st to the 4th day, dexamethasone 40 mg p.o. or i.v. always on 4 days starting with the 1st, 10th and 20th days, cyclophosphamide 600 mg i.v. on the 5th, 10th and 20th days). A further cycle follows on the 28th day. In the present paper the effect and the tolerance of this C-VAD scheme is evaluated: In the group of 21 patients with refractory myeloma 9 remissions were achieved, 5 partial remissions, in 6 patients the disease progressed, 1 patient died after the 2nd cycle without the possibility of evaluating the therapeutic response. The mean remission length was 10.2 months. The tolerance of chemotherapy was satisfactory, C-VAD chemotherapy did not cause any serious drop in the number of leucocytes and thrombocytes. Echocardiographically lower adriamycin cardiotoxicity was demonstrated in continual administration in comparison with the bolus administration. The C-VAD scheme is considered to be suitable for comparison with the VAD chemotherapy in a randomized study.