Frail elderly in the community, in nursing homes or in hospitals are at increased risk of malnutrition. In many instances, their existing nutritional disorders go unrecognised and adversely affect their health, ability to overcome disease, and so is associated with poor clinical outcome. The prevalence of malnutrition ranges from 5-10% in free-living elderly to 30-85% in homebound, nursing home, and hospitalised elderly. Possibilities exist to prevent or correct this malnutrition, but have not been frequently used until now due to the lack of a specific validated tool to screen for malnutrition. The goal of the Mini Nutritional Assessment (MNA) is to determine who is at risk of malnutrition, and hence to permit early nutritional intervention. It has been designed for easy use by general practitioners as well as health professionals involved in admitting patients to hospitals and nursing homes. The test, which comprises simple measurements and a brief questionnaire, can be performed in about 10 minutes. It involves: anthropometric assessment (weight, height and weight loss) general assessment (lifestyle, medication and mobility) dietary assessment (number of meals, food and fluid intake, autonomy of eating self assessment (self-perception of health and nutrition). The MNA has now been validated in three studies involving more than 600 elderly individuals, from the very frail to the very active in free-living and long-term care environments. The MNA was validated against a clinical evaluation and a comprehensive nutritional assessment. It can classify the elderly as well-nourished, undernourished, or at risk of malnutrition. The MNA can be an important tool in evaluating the risk of malnutrition in the elderly, if integrated into geriatric assessment programs.