A review of research into cancer-related fatigue undertaken since 1995 is presented. The manner in which such fatigue varies with cancer diagnosis, stage of disease and anti-cancer treatment is discussed, and the causes of cancer-related fatigue are categorized according to whether they are cancer-specific, common to other chronic illnesses or common to the general population. Interventions to alleviate fatigue are discussed in terms of whether they are pharmacological or non-pharmacological in nature. It is concluded that cancer-related fatigue is a common problem with a major impact on quality of life. It shares a common aetiology with other forms of fatigue. Graded aerobic exercise has been shown in randomized controlled trials to be an effective intervention in specific patient groups. Less direct evidence supports the use of psychological interventions, but there is very little evidence to support the use of pharmacological treatment, with the possible exception of erythropoietin therapy for anaemic patients undergoing chemotherapy.