Multiple myeloma (MM) is a plasma cell dyscrasia characterized by malignant proliferation of monoclonal plasma cells in the bone marrow. Interphase fluorescence in situ hybridization (I-FISH) required for revised international staging system (R-ISS) classification in MM risk classification is not available in every medical center. CRAB findings were suggested to be an easy and practically applicable marker for MM prognosis. In this study, we aimed to examine the effect of CRAB and SLiM factors, which are among the myeloma defining events, on progression-free survival and overall survival of the MM patients. Sixty six MM patients who applied to Diskapi Yildirim Beyazit Training and Research Hospital Hematology Clinic for treatment and follow up between 2012 and 2021 were included in the study. Patients in this study were between the ages of 39-86.The number of male patients in the study was 36 (54.5%). In the multivariate analysis, the most important factors affecting the overall survival of the patients were identified as M protein type, bone marrow plasma cell ratio ≥ 60% and autologous stem cell transplantation (p= 0.019, p= 0.007, p= 0.04, respectively). Multivariate analysis revealed that the only factor affecting the progression-free survival of the patients included in the study was the presence of extra medullary plasmacytoma (p= 0.014). In conclusion, CRAB criteria are not related to overall survival. CRAB criteria cannot replace R-ISS, contrary to what is suggested in some studies in the literature. Bone marrow plasma cell ratio,which is one of the SLiM criteria, affects overall survival. SLiM criteria may be more important than CRAB criteria as a practical and easy prognostic marker that can be substituted for R-ISS.