The anaemia of chronic disease is the second most common anaemia in the world and is an underproduction anaemia with relatively low erythropoietin (EPO) values for the degree of the anaemia. This anaemia occurs with inflammation, infection, or malignancy and a principle question has been whether it would respond to recombinant human EPO (r-HuEPO). Several studies are now available to answer this question. In one study 12 of 16 patients with rheumatoid arthritis receiving r-HuEPO increased their haematocrits 6 percentage points or more and 11 of 12 reached normal haematocrits. Investigations of the effect of r-HuEPO on the anaemia of AIDS showed that patients with EPO levels of 500 U/L or less had an increase in the mean haematocrit of 4.6 percentage points with a decrease in red cell transfusions from 5.3 to 3.2 units per patient. Quality of life indices significantly improved in responders. When 413 patients with anaemia due to a wide variety of malignancies were randomized to r-HuEPO treatment, 58% of those receiving chemotherapy increased their haematocrits by at least 6 points over 12 weeks. Quality of life parameters of responders also significantly improved. Anaemia in three patients with inflammatory bowel disease also responded in 8-14 weeks to r-HuEPO and two of the three reached normal haemoglobin levels. It is clear that r-HuEPO can correct the anaemia of chronic disease and can improve the quality of life of responders.