In the past 20 years, an increased interest geriatric nutrition has induced researchers to document the distribution and magnitude of nutritional problems in the elderly population. It has been observed that the prevalence of malnutrition is greatly affected by the general health status and autonomy of the elderly. Among free-living healthy elderly persons, the prevalence of protein-caloric undernutrition is low. As health and functional capacities deteriorate with age, however, the prevalence increases dramatically to 30-65% of those in home care, nursing homes or in hospital. Formal nutritional assessment has typically been absent from most published programmes of geriatric evaluation and comprehensive geriatric assessment. This is frequently because of the lack of a specific validated tool to assess nutritional status in older persons and, at least partly, to explain this phenomenon. The Mini Nutritional Assessment was developed and validated on large representative samples of elderly persons to address these specific issues. Recent experimental studies have shown that advanced malnutrition is much more difficult to treat in the elderly than in younger adults. Trials of nutritional support using oral supplements or enteral tube feeding have shown improved outcome in those identified as malnourished on admission to hospital.