Background: Given the role of inflammation in tumor progression, as well as in diffuse large B-cell lymphoma (DLBCL), researchers are trying to identify easily applicable, easy accessible prognostic markers for individual risk assessment. The most frequently used inflammatory prognostic markers are the neutrophil-to-lymphocyte ratio (NLR), the platelet-to-lymphocyte ratio (PLR),andthe Glasgow prognostic score (GPS). Objectives: To determine and compare the prognostic value of the baseline inflammatory biomarkers NLR, PLR, and GPS in patients with DLBCL. Methods: We retrospectively analyzed data from 103 DLBCL patients treated with R-CHOP or R-CHOP-like regimens. We evaluated the significance of NLR, PLR, and GPS as a predictor of response to treatment, overall survival (OS), and event-free survival (EFS). Results: Higher NLR levels were found in patients with a poorer response to therapy (median [range] 2.87 [0.56 - 26.33] vs. 4 [0.62 - 29.66], P = 0.026). Patients with NLR values of > 2.63 (cutoff value calculated by receiver-operating characteristic) had significantly worse two-year OS (65.1% vs. 87.2%, P = 0.002) and two-year EFS (59.8% vs. 87.1%, P = 0.001). PLR values were not significant for survival. The two-year OS rates for patients with GPS = 0, GPS = 1, and GPS = 2 were 93.3%, 63.9%, and 33.3%, respectively (P < 0.001), and EFS rates were 86.5%, 65.3%, and 30.3%, respectively (P < 0.001). Cox regression analysis showed that only NLR values of > 2.63 were an independent prognostic factor for OS (hazard ratio [HR] = 2.857; 95% confidence interval [CI] 1.022 - 8.699; P = 0.048] and EFS (HR = 4.06; 95% CI 1.357 - 12.151; P = 0.012). Conclusions: Our research confirmed NLR as useful independent prognostic marker for survival. PLR and GPS did not show independent prognostic value, although they were also associated with the patients’ clinical features. The easy availability and inexpensiveness of inflammatory biomarkers should encourage their use in clinical practice.