Apparition of new tools in the therapy of multiple (MM) strengthens the need for valuable prognostic categorization of each patient in order to propose the most adequate treatment. Prognostic factors in MM can be divided in four groups. The first, including beta 2 microglobulin (beta 2m), hemopoiesis impairment, osteolytic lesions, calcemia and albuminemia, reflects the tumor mass. The second: type of monoclonal component, labeling index (LI), C-reactive protein (CRP), cytologic, histologic and immunophenotypic aspects of plasmocytes, renal biology, ADN and ARN, contents of malignant cells, LDH levels, activation of ras oncogene represents the intrinsic malignancy of the clone. The third illustrates the type of response to chemotherapy. Finally, the last group characterizes the host and his reactivity against the disease. Thus, the referential prognostic classification of Durie and Salmon representing only the tumor burden, seems to be now insufficient. New classifications including CRP, beta 2m and LI as more discriminant parameters are currently proposed.