The frequency of snoring was studied in 46 patients with Alzheimer's disease (AD), 37 with multiinfarct dementia (MID), and in a random sample of 124 elderly community residents without known diseases affecting higher cortical functions. The demented patients were reported to snore twice as frequently as the control subjects (P less than 0.05). No difference in the frequency of snoring was present between the patients with AD and MID. In contrast to younger populations, snoring was not significantly associated with cardiovascular morbidity in this elderly population.