This review is an update of a previously published update review in The Cochrane Database of Systematic Reviews (Issue 4, 2006) on this topic. No new studies have been identified from the update search and the conclusions are not altered. Supportive care has traditionally been given to optimise the comfort of patients and their ability to function, as well as to minimise the side-effects of anti-cancer treatments. However, the scope of modern comprehensive supportive care is broadening and covers not only specific palliative treatment but non-tumour specific treatment such as social, psychological and spiritual support. In oncology, best supportive care (BSC) has been used as a comparator arm of randomised controlled trials in chemotherapy. However, the BSC arm is usually not well defined and its evaluation is therefore difficult because of the heterogeneity of the definitions. A systematic review was undertaken of the evidence from all RCTs of gastrointestinal cancers (includes gastrointestinal/gastric, colorectal/colon cancer but excludes pancreatic cancer trials) which include a BSC/SC arm.