Amongst factors associated with the institutional placement of elderly people with dementia, there has been little study of those related to malnutrition. We followed a cohort of 318 individuals with Alzheimer's disease (AD). Patients, who were all living at home at the start of the study were recruited from the outpatient service of a hospital unit specialising in AD. After one year, 20% of the patients had moved into institutional care. Multivariate analysis showed that a Mini nutritional Assessment score (MNA) of less than 25.5 (median score of the sample) and overeating behavioural problems (p=0.006) were risk factors for institutional placement. Nutritional problems are reversible and patients with a low MNA score could benefit from a thorough geriatric assessment, in order to slow or prevent institutional placement.