Background and Aim: Immunohistochemistry may serve as a surrogate to define Diffuse large B-cell lymphoma (DLBCL) cases as germinal center B cell-like (GCB) or non-GCB subtypes and to provide prognostic information. In this study, we aimed to investigate the frequency and prognostic impact of CD10, B-cell lymphoma 2 and 6 (BCL2 and BCL6) and multiple myeloma oncogene 1 (MUM1) expressions in pathology sections of patients with DLBCL to determine the response of these subgroups to the rituximab including chemotherapy regimens. Materials and Method: Patients were grouped into 2 regarding the chemotherapy regimens they were treated, as cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP) or Rituximab-CHOP. The treatment response, follow-up periods and outcomes of patients were recorded. The immunohistochemical panel was stained in pathology sections for CD10, BCL6 and MUM1/IRF 4 biomarkers. The patients were subgrouped as GCB or ABC regarding the immunohistochemical panel. Results: Totally 81 patients, (39 male, 42 female) were included in the study. At the time of diagnosis, CD10 was positive in 31 patients (38.3%); BCL-6 in 53 patients (65.4%); MUM-1 was positive in 47 patients (58%) and BCL-2 was positive in 53 patients (65.4). With these results, 36 patients (44.4%) were in the GCB group and 45 patients (55.6%) were in the ABC group. No significant difference was found between the individual markers and subgroups in survival analyses. Conclusion: We did not determine any significant effect of CD10, BCL-6, MUM-1 or BCL-2 positivity or GCB and non-GCB groups in the survival of patients with DLBCL.