Preoperative anemia is a common finding in patients undergoing colorectal surgery, particularly those with cancer. While often multifactorial, iron deficiency anemia remains the most common cause of anemia in this patient population. Although seemingly innocuous, preoperative anemia is associated with an increased risk of perioperative complications and need for allogenic blood transfusions, both of which may worsen cancer-specific survival. Preoperative correction of anemia and iron deficiency is thus necessary to diminish these risks. Current literature supports preoperative screening for anemia and iron deficiency in patients slated to undergo colorectal surgery for malignancy or for benign conditions with associated patient- or procedure-related risk factors. Accepted treatment regimens include iron supplementation-either oral or intravenous-as well as erythropoietin therapy. Autologous blood transfusion should not be utilized as a treatment for preoperative anemia when there is time to implement other corrective strategies. Additional study is still needed to better standardize preoperative screening and optimize treatment regimens.