Thirty elderly subjects with dementia were assessed using a neuropsychological test battery. Using four cognitive and behavioural measures of severity of dementia, no significant relationships between National Adult Reading Test (NART) or Mill Hill Vocabulary Scale synonym section (MHVS) scores and severity were observed. The NART and MHVS correlated with each other to a highly significant degree. No differences were observed on any of the measures when patients with Alzheimer's disease were compared with those adjudged to have multi-infarct dementia. These results are discussed in relation to the existing literature on the estimation of premorbid intelligence in dementia.