Objective: To optimize preoperative transfusion strategies and take necessary precautions, determining the high risk patients for bleeding is important. In this study, it was aimed to investigate immunologic and non-immunologic determinants of the transfusion requirements. Material and Methods: Thirty three patients were included in the study. During the preoperative period all patients were assessed in terms of immunologic (TNF-α, IL-10), non- immunologic-patient dependent (age, gender, ejection fraction (EF), Hct, Hb, creatinine and the INR levels) and non-immunologic surgery- dependent (temperature and Hb levels during cardiopulmonary bypass (CPB) period, CPB duration) parameters. During the operation, patients were transfused to achieve a target of Hb 7-8 gdL-1, ≥25% Hct and those who were transfused < 2 and ≥ 2 packs of red blood cell received. Results: Twenty nine patients were transfused < 2 packs and 4 of them ≥ 2 packs of red blood cells. Immunologic variables did not correlate with the amount of transfusion. The patients transfused ≥ 2 packs of red blood cells perioperatively were determined to have lower Hb, Hct and ejection fraction preoperatively and prolonged operative times for cardiopulmonary bypass but this finding was not statistically significiant. Conclusion: The results of our study showed that TNF-α and IL-10 levels are not determinants of perioperative blood transfusion requirements. Also, a statistically important correlation was not found between non- immunologic factors and transfusion requirements. Larger scale investigations related to these group of determinants were thought to be beneficial.