With the considerable cost of disease-related malnutrition to individuals and to society (estimated to be >£13×109 for the UK, 2007 prices), there is a need for effective and evidence-based ways of preventing and treating this condition. The wide range of oral nutritional supplements that may be prescribed for the dietary management of malnutrition and other conditions account for only about 1% (about £99×106, 2007 data) of the prescribing budget in England. Systematic reviews and meta-analyses consistently suggest that ready-made, multi-nutrient liquids which may be prescribed can improve energy and nutritional intake, body weight and have a variety of clinical and functional benefits in a number of patient groups. Meta-analyses have repeatedly shown that oral nutritional supplements produce significant reductions in complications (e.g. infections) and mortality, and a recent meta-analysis shows a reduction in hospital admissions (OR 0·56 (95% CI 0·41, 0·77), six randomised controlled trials). Such benefits suggest that the appropriate use of oral nutritional supplements should form an integral part of the management of malnutrition, particularly as there is currently a lack of evidence for alternative oral nutrition strategies (e.g. food fortification and counselling). As with all therapies, compliance to oral nutritional supplements needs to be maximised and the use monitored. To make sure that those at risk of malnutrition are identified and treated appropriately, there is a need to embed national and local policies into routine clinical practice. In doing so, the economic burden of this costly condition can be curtailed. As recently suggested by the National Institute for Health and Clinical Excellence, substantial cost savings could be made if screening and treatment of malnourished patients was undertaken.