Refeeding syndrome (RS) is a potentially serious but underrecognized phenomenon in geriatric medicine. It can occur in malnourished elderly subjects when feeding is re-introduced after a period of fasting. The clinical presentation of RS is unspecific, and it is often accompanied by psychomotor impairment suggestive of delirium. In this article, illustrated by 2 clinical cases, we report a series of 13 patients with RS, of whom 11 had delirium. Treatment of RS is based on progressive refeeding and phosphate, magnesium, potassium and thiamine supplementation. This combination leads to favorable outcome and disappearance of delirium in a majority of patients.