Background: Blood transfusion is needed in patients following open-heart surgery; however, it may lead to the incidence of infection, increased mortality, and longer hospitalization. This study was designed to evaluate the outcome of blood transfusion in patients who underwent cardiac surgery. Methods: The present study enrolled 784 candidates for open-heart surgery at our tertiary care center between April 2012 and 2013. The study outcomes were defined as sepsis, mediastinitis, pneumonia, mortality, extubation times more than 8 hours after surgery, and intensive care unit (ICU) lengths of stay of more than 3 days. Results: There was a significant association between packed cell transfusion and the incidence of pneumonia, sepsis, prolonged intubation times, surgical site infections, and prolonged lengths of ICU and hospital stay (P < 0.05); however, there was no significant association between packed cell transfusion and mortality (P = 0.2). There was a significant relationship between fresh frozen plasma transfusion and the incidence of all types of surgical complications, mortality, and prolonged ICU and hospital lengths of stay (P < 0.05). There was a significant association between platelet transfusion and the incidence of pneumonia, mediastinitis, prolonged intubation times, surgical site infections, and prolonged lengths of ICU and hospital stay (P < 0.05); nonetheless, there was no significant association between platelet transfusion and mortality (P = 0.1). In the multiple logistic regression, an association was observed between age, sex, and complications following adjustments for packed cell transfusion, fresh frozen plasma, and platelet. Conclusions: The administration of blood and hemo-components was associated with the development of postoperative complications such as sepsis, mediastinitis, pneumonia, mortality, prolonged intubating times, and prolonged lengths of ICU and hospital stay.