The development of alternatives to hospitalisation is mandatory in cancer patients. A retrospective analysis compared the costs relative to two modalities of administration of VAD chemotherapy (hospital versus outpatient) in multiple myeloma. This study was carried out from the perspective of the French health care system, including direct hospital and ambulatory costs. The robustness of results was tested in a sensitivity analysis. Forty four patients were included: 27 in the "hospitalisation" arm and 17 in the "outpatient" arm. Among the cycles planned to be administered in outpatient, only 5 cycles (4 patients) have to be administered in hospital. The length of hospitalisation was consequently reduced with outpatient administration (-11.2 days) and it induced a significant cost saving as 3,066 euros (-32%) per patient. In sensitivity analysis, this cost saving varied from 1,282 to 3,667 euros. Our study showed the safety and the economic interest of outpatient administration of VAD chemotherapy in multiple myeloma. Facilities and training are required to develop ambulatory chemotherapy.