AbstractThe more common causes of anemia in malignant disease are discussed. Of 78 patients requiring transfusions on the Oncology Service of the University of Wisconsin Medical Center during the period December 1968–May 1969, records were available on 65. Gross blood loss was the most common cause of the anemia (44 cases); next was suppression of the bone marrow by chemotherapy (27 cases) or radiation therapy (8 cases); tumor spread to bone marrow (18 cases); infection (15 cases); uremia (5 cases); and poor nutrition (5 cases). Directions are given for evaluation of the patient.The search for the cause of the anemia should be intensive, for only in this way can the proper diagnosis be made and the appropriate treatment recommende