There is evidence in the literature that oral nutritional supplements, total enteral and parenteral nutrition can expand life expectancy and improve quality of life in patients suffering from undernutrition. In the present review, we outline whether these treatments regimens are also effective in severely ill patients. Moreover, the usefulness of nutritional interventions in patients sick unto death, e.g. by stroke, cancer or dementia, is broadly discussed. The controversy about terminal dehydration is shortly reviewed.