Objective The aim was to explore the effectiveness of the International Myeloma Working Group Frailty Index (IMWG-FI), Mayo Score, UK Myeloma Research Alliance Risk Profile (MRP), and Intergroupe Francophone du My & eacute;lome (IFM) simplified frailty scale for classifying frailty in elderly multiple myeloma (MM) patients and compare the validity of different frailty tools. Methods Eighty-four newly diagnosed MM patients aged >= 60 years in HeBei University Hospital were evaluated by the IMWG-FI, Mayo score, MRP score and IFM scale, and consistency and survival analyses were performed using Cohen's kappa coefficients and the Kaplan-Meier method, respectively. Results A total of 64 patients (76.2%) were identified as frail by at least one frailty tool; 14 (21.9%) were identified as frail by all four tools, and although moderate concordance was achieved between the IMWG-FI and MRP and the Mayo Score (0.432-0.474, P < 0.001), the concordance among the four assessment tools was relatively low (Cohen's kappa 0.218-0.474). The median overall survival (OS, P = 0.006, 0.025, and 0.028) and progression-free survival (PFS, P = 0.002, 0.006, and 0.03) of patients in the frail group and the nonfrail group identified by the IMWG-FI, Mayo score, and MRP were significantly different, while the median OS (P = 0.139) and PFS (P = 0.167) were not significantly different for the frail patients identified by the different frailty assessment tools. Conclusion In this study, the consistency of the different frailty assessment tools was low, whereas that between the MRP and IMWG-FI was high. Therefore, combining IMWG-FI and MRP may reduce assessment subjectivity and improve frailty identification.