Anemia is a real and frequent complication during the management of cancer patients. It is define as a decrease of the erythrocyte mass. The hemoglobin rate (which was an estimation of this erythrocyte mass) is the most often using criteria. The inferior threshold change with the sex and the age of the patients. This is 13 g/dl for the men and 11.5 g/dl for the women. This rate would be however decrease without any other associated pathology. This anemia is due to nutritional context of the patients and complications of the cancer pathology or his management (treatments). Anemia due to the chemotherapy toxicity is a real problem to investigate, to quantify, to prevent or to treat. The chemotherapy toxicity worsened previous anemia (inflammatory ethiology) which physiopathology is multifactoriel and depends on drugs, patients' characteristics, and sort of cancer. Anemia is also a therapeutic problem. Whatever is the severity of the anemia, impact on the quality of life with physical and social consequences is clear. In addition, anemia could relieve of specific treatment such as blood transfusion or preventive treatment with recombinant erythropoietin.