Objective：This study investigated the clinical significance of red blood cell distribution width（RDW）in Waldenstrom macroglobulinemia（WM）. Methods：Data of patients diagnosed with WM in the First Affiliated Hospital of Nanjing Medical University from June 2009 to September 2018 were retrospectively analyzed. The best cut-off value of RDW was determined by receiver operating characteristic（ROC）curve. Univariate and multivariate analysis were performed to find out the factors of progression-free survival（PFS）and overall survival（OS）. Results：Seventy-eight patients were finially enrolled in this study. The ROC curve indicated that 16.4% was the best cut-off value to predict survival outcomes. The median follow-up time was 39.5 months，patients with a high level of RDW（＞16.4%）had worse survival outcome. Multivariate analysis revealed that a high level of RDW was an independent risk factor for PFS and OS. Furthermore，a high level of RDW together with the revised international prognostic score system for WM improved the prognostic capacity of WM. Conclusion：RDW is a feasible clinical parameter which could be used to predict the prognosis of WM.