Malnutrition is common in older people and is associated with a number of adverse outcomes. We review the evidence for the effectiveness of nutritional supplementation for older people in the community, in institutional care and following discharge from hospital. Studies in these settings are scarce, often include only small numbers of participants and are of variable quality. The interventions used are heterogeneous and difficult to directly compare. Oral nutritional supplements (sip feeds), dietary fortification, educational programmes, exercise, flavour enhancement and meal setting have all been studied. Evidence for use of oral nutritional supplements as sip feeds in undernourished community-dwelling and institutionalized older people and in those discharged from hospital is currently insufficient to recommend routine use. Flavour enhancement and more sociable meal environments may be beneficial. Further, more methodologically robust research is needed to clarify the effect of these interventions.