Using a prospective case series design, we examined the incidence of oropharyngeal swallowing abnormalities in 25 patients with moderate or severe Alzheimer's disease by videofluoroscopy. Aspiration occurred in 6 of 25 (28.6%). Only four patients showed unequivocally normal performance. Exploratory statistical analyses showed that swallowing abnormalities associated significantly with duration of dementia, eating dependency, and abnormal oral praxis. We observed a trend toward a higher incidence of aspiration in patients with more severe dementia. We conclude that oropharyngeal swallowing abnormalities, including aspiration, are more prevalent in patients with Alzheimer's disease than in normal elderly individuals.