Anaemia is defined by the presence of haemoglobin (Hb) levels < 13 g/dL in men and 12 g/dL in women. Up to 39% of cancer patients present it at the time of diagnosis and up to 40% have iron deficiency. Anaemia causes fatigue, functional deterioration and a reduction in the quality of life; it has also been associated with a poorer response to anti-tumour treatment and lower survival. Basic diagnostic tests for anaemia are simple and should be a routine part of clinical practice. These guidelines review the available evidence on the use of different therapies for treating anaemia: erythropoiesis-stimulating agents, iron supplements, and transfusion of blood products.