Preoperative, operative, and postoperative factors may all contribute to high rates of anemia in patients undergoing surgery for cancer. Allogeneic blood transfusion is associated with both infectious risks and noninfectious risks such as human errors, hemolytic reactions, transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, and transfusion-related immune modulation. Blood transfusion may also be associated with increased risk of cancer recurrence. Blood-conservation measures such as preoperative autologous donation, acute normovolemic hemodilution, perioperative blood salvage, recombinant human erythropoietin (epoetin alfa), electrosurgical dissection, and minimally invasive surgical procedures may reduce the need for allogeneic blood transfusion in elective surgery. This review summarizes published evidence of the consequences of anemia and blood transfusion, the effects of blood storage, the infectious and noninfectious risks of blood transfusion, and the role of blood-conservation strategies for cancer patients who undergo surgery. The optimal blood-management strategy remains to be defined by additional clinical studies. Until that evidence becomes available, the clinical utility of blood conservation should be assessed for each patient individually as a component of preoperative planning in surgical oncology.