Naming impairment is a common feature of the language disorder of dementia, yet agreement has not been reached on its mechanisms. In this study, the confrontation naming performance of twelve demented subjects was compared to that of age-matched controls. Naming deficits were studied in relation to overall language and cognitive dysfunction and analysed to assess the importance of both perceptual and linguistic factors. Naming dysfunction occurred even in mild dementia, in patients whose overall language function remained normal, and worsened in proportion to the degree both of language deficit and overall cognitive dysfunction. Perceptual difficulty and word frequency, but not word length, were important determinants of naming performance in demented patients.