Using a telephone survey, patients with probable Alzheimer's disease (n = 31) and vascular dementia (n = 14) were compared with elderly normal controls (n = 43) in preferences for different foods. Patients with Alzheimer's disease had a greater preference than normal controls for relatively high-fat, sweet foods and for high-sugar, low-fat foods, but did not significantly differ in preference for other foods, including those high in complex carbohydrates and protein. Vascular dementia patients showed a similar pattern, not significantly different from that for Alzheimer's patients. Results did not consistently support a hypothesis that increased sweet preference is a nonspecific form of disinhibited behavior related to declining mental status, nor was a hypothesis relating sweet preference to serotonin activity within the brain consistently supported. Results provide preliminary evidence that craving for sweet food may be a significant part of the clinical syndrome of dementia, but further research is needed to delineate the psychological and biological mechanisms accounting for it.