The neuropsychological performance (including measures of language, semantic memory, visual and spatial perception and executive functions) of a group of 14 patients with the clinical diagnosis of probable frontotemporal dementia was compared with that of a group of 14 patients with a clinical diagnosis of probable Alzheimer's disease. The aim was to identify a specific cognitive profile of frontotemporal dementia, which could be used to select a sensitive, short evaluation for the differential diagnosis with Alzheimer's disease. Both groups were severely impaired in most tasks, including those 'frontal lobe' tests which have been suggested to play an important role in differential diagnosis. Significant differences were found only for a minority of tests (oral praxis, visual-spatial perception, and verbal fluency). A logistic regression showed that a shortened testing procedure based on four tests (Rey-Osterreith complex figure test recall, phonemic fluency, oral apraxia, and cube analysis) achieved a 70% sensitivity and 80% specificity for the correct classification of patients in the frontotemporal dementia or Alzheimer's disease group. In conclusion, a brief neuropsychological evaluation including these four tests, as well as other measures sensitive to the frontal impairment, can be useful in the differential diagnosis between the two pathologies, along with the clinical data.