Many kinds of degenerative, psychiatric, and cerebrovascular diseases can mimic behavioral variant frontotemporal dementia. We present a 73-year-old woman who presented with apathy, inappropriate social behavior, and persecutory delusion. A neuropsychological examination revealed frontal/executive dysfunction with relative sparing of episodic memory. Magnetic resonance imaging and F-18 fluorodeoxyglucose positron-emission tomography produced normal findings. However, magnetic resonance angiography revealed severe right internal carotid stenosis. After carotid stenting, her behavioral symptoms disappeared and did not recur during an 18-month follow-up.