Background/aim: Blood transfusion is associated with immunosuppression, referred to as transfusion-related immunomodulation (TRIM). In this study, for the first time, changes in the concentration of TGF-ß and TNF-α were measured postoperatively in orthopedic patients with intraoperational allogeneic red blood cell transfusion. Considering the use of packed cell units with different ages, it is possible to suggest the more appropriate product for clinical applications.Materials and methods: Two groups of 35 orthopedic surgery patients (with or without transfusion as case and control groups, respectively) were involved. Serum levels of TNF-α and TGF-ß were measured by ELISA.Results: The data suggested significant differences in age (P = 0.0001), lowered hemoglobin (P = 0.003), and hematocrit (P = 0.003) between the control and case groups. Pre- and postoperation levels of TNF-α and TGF- ßwere not significantly different, but the results showed significant increases in levels of both cytokines after the operation (P = 0.0001) in both groups.Conclusion: Increased levels of TNF-α and TGF-ß are probably related to surgery and packed cell transfusion, respectively. Further studies using more packed cell units or other blood products and assessment of more cytokines are needed to have better understanding about this issue.