This study aims to investigate the prognostic significance of the MYC protein expression in diffuse large B cell lymphoma (DLBCL) patients treated with RCHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone). A total of 60 patients with DLBCL from 2008 to 2013 were included. Formalin-fixed, paraffin-embedded DLBCL samples were analyzed for MYC protein expression and divided into high or low MYC group. The MYC protein expression and the international prognostic variables were evaluated. The high MYC protein expression predicted a shorter 3-year estimated overall survival (OS) and progression-free survival (PFS) versus the low MYC protein expression (57 % vs. 96 %, P < 0.001 and 50 % vs. 96 %, P = 0.001, respectively). Multivariate analysis confirmed the prognostic significance of the MYC protein expression for both OS (HR, 11.862; 95 % CI, 1.462-96.218; P = 0.021) and PFS (HR, 6.073; 95 % CI, 1.082-34.085; P = 0.040). MYC protein expression with International Prognostic Index (IPI) score distinguished patients into three risk groups with different 3-year OS rates (χ (2) 23.079; P < 0.001) and distinct 3-year PFS rates (χ (2) 15.862; P < 0.001). This study suggests that the MYC protein expression is an important inferior prognostic factor for survival in patients with DLBCL treated with RCHOP. The combinative model with IPI score and MYC protein expression could stratify DLBCL patients into prognostically relevant subgroups more effectively than either the IPI or the MYC alone.