In a multicenter study, FDG-PET images in a population of 29 patients with frontotemporal dementia (FTD) were compared to controls with similar age from each center. A conjunction analysis led to identification of the ventromedial frontopolar cortex as the single region affected in each and every FTD patients. This precise regional metabolic impairment should be integrated with recent neuropsychological researches, such as those showing that the ventromedial frontal cortex is critically involved in decision-making processes based on personal experience, feelings of rightness or social knowledge, processes that are characteristically impaired in FTD.