Capgras' syndrome is characterized by a subjective certainty that a familiar person has been replaced by an identical double. This syndrome has been observed in psychiatric and neurological diseases, and has been reported in several cases of dementia of the Alzheimer type. Here, we present a patient with vascular dementia in whom Capgras' syndrome developed in the early stages of dementia, and who exhibited violence. This case suggests that Capgras' syndrome can occur in vascular dementia. In older patients with this syndrome, dementia should also be considered in its differential diagnosis. In addition, patients with Capgras' syndrome should be evaluated for violent potential.