BackgroundThe significant role of red blood cell distribution width (RDW) and D‐Dimer as prognostic factors in patients with some blood malignancies has been reported recently.AimWe designed and performed a meta‐analysis to investigate the prognostic roles of RDW and D‐Dimer in subjects with diffuse large B‐cell lymphoma (DLBCL).Materials and MethodsWe systematically reviewed PubMed‐Medline, SCOPUS, EMBASE, Web of Science Core Collection, and Google Scholar up to the present to look for publications on prognostic effects of RDW and D‐Dimer in DLBCL patients. For investigation of the associations between RDW and D‐Dimer with the overall survival (OS) and progression‐free survival (PFS) of the DLBCL cases, hazard ratio (HR) with 95% confidence intervals (CIs) was used.ResultsWe included 13 eligible studies in the present meta‐analysis. The results of pooled analysis showed that increased levels of RDW was related to poor OS (HR = 2.01, 95% CI: 1.62–2.48, p value <.01, I2 = 0%) and poor PFS (HR = 1.52, 95% CI: 1.24–1.85, p value <.01, I2 = 16%) among the DLBCL patients. Similarly, a significant relationship was found between increased D‐Dimer and poor OS (HR = 2.30, 95% CI: 1.03–5.14, p value <.05, I2 = 95%) of the DLBCL patients as well. In addition, there was no significant heterogeneity in OS (p value H = 0.65) and PFS (p value H = 0.31) related to RDW among studies included in the meta‐analysis.ConclusionOur finding clearly confirmed that elevated RDW levels and D‐Dimer were associated with adverse OS and PFS in DLBCL.