Surgical patients are at risk of postoperative complications and mortality, necessitating preoperative patient optimization through the identification and correction of modifiable risk factors. Although preoperative platelet transfusions aim to reduce the risk of bleeding, their efficacy remains uncertain. Similarly, red blood cell transfusion in patients with anemia does not reduce the risk of postoperative mortality and may exacerbate complications. Therefore, developing individualized strategies that focus on correcting preoperative complete blood count abnormalities and minimizing transfusion requirements are essential. This review aimed to examine complete blood count abnormalities and appropriate transfusion strategies to minimize postoperative complications.