The relative fluency with which 15 patients with Alzheimer-type dementia (DAT) retrieved words with specified first letters and belonging to semantically defined categories was assessed. Patients with DAT were always less fluent than controls but, like the 12 normal elderly subjects, they were more efficient in accessing words belonging to semantic categories. Their deficit in retrieving words with specified first letters was greater than that predicted on the basis of verbal intellectual ability. No differences in word fluency were detected in presenile and senile patients. These data support the conclusion that word fluency may prove useful in the detection of early dementia.