BackgroundSome studies have investigated the prognostic value exhibited by the Prognostic Nutritional Index (PNI) in patients suffering diffuse large B-cell lymphoma (DLBCL), but varying results were obtained. In order to determine the specific prognostic value more accurately, a meta-analysis was conducted in this study.MethodsLiteratures were searched from the China National Knowledge Infrastructure (CNKI), Wanfang, PubMed, Embase, the Cochrane Library, and Web of Science. Pooled hazard ratio (HR) and the 95% confidence interval (CI) were calculated to assess the association between PNI and the overall survival (OS) and the progression-free survival (PFS) of patients with DLBCL.ResultsBased on seven studies with a total number of 1311 patients, our meta-analysis revealed that low PNI may meant poor OS (HR = 2.14, 95% CI 1.66–2.75, p < 0.001) and poor PFS (HR = 1.75, 95% CI 1.36–2.25, p = 0.438). Subgroup analysis showed that, in Asians, low PNI was correlated to poor OS (pooled HR = 2.06 95% CI 1.59–2.66) and poor PFS (pooled HR = 1.66, 95% CI 1.28–2.15). Similar results were obtained from one European study, which is the only study performed outside of Asia from our literature search.ConclusionFor patients with DLBCL, low PNI may be interpreted as adverse prognosis. More data from European patients are required in this study to avoid analysis bias.