We studied the characteristics of the naming disorder of dementia of the Alzheimer type (DAT) in 20 patients, who were divided on the basis of Mini-Mental State scores into a mild and a moderate-severe group. Our results confirmed the presence of a progressive anomia which was sensitive both to word frequency and to image quality. Although DAT patients as a group made a similar proportion of perceptual-recognition and aphasic errors as did our age and education-matched controls, evidence was obtained that suggested that variations in the character of the anomia exist among individual DAT patients.