Abstract : Ageing of the body predisposes to a high incidence of undernutrition in the elderly person wherever he or she is living, but the prevalence of malnutrition is particularly high in hospitalized or instutionalized patients. Early detection of malnutrition is important because malnutrition may have significant consequences and evaluation of nutritional status has to be a routine screening in the elderly. There is nosingle parameter which supplies a full assessment of the patient’s nutritional status. It is then necessary to use screening tools for the identification of patients at nutritional risk, based on anamnestic, antropometric and biologic data. The MNA (Mini Nutritional Assessment) test is a simple, non invasive, well-validated screening tool for malnutrition in the elderly and is recommended for early detection of risks on malnutrition. Numerous conditions in relationship with physiological ageing, comorbidity, polymedication and the way of life of the individual predispose to undernutrition. Healthy nutrition in older patients should respect the guidelines for protein and energy requirements, excepted in severely ill patients and/or in case of malnutrition in which case the protein-energy intake should be increased