Acupuncture can increase both cerebral oxygen saturation and cerebral blood flow velocity. We describe a 77-year-old woman with cerebrovascular dementia in whom acupuncture reproducibly induced an increase of blood flow velocity but a decrease of regional oxygen saturation. At four of 11 acupuncture sessions, blood flow velocity was measured in the middle cerebral artery with transcranial Doppler sonography and cerebral regional oxygen saturation (rSO(2)) with transcranial near infrared spectroscopy. Cerebral blood flow velocity increased by an average of 20% (range: 7-27%) at all four study points whereas rSO(2) consistently decreased by an average of 7% (range: 4-13%). Clinical status and cognitive function improved. These findings in a patient with vascular dementia may suggest increased oxygen extraction by activated neuronal structures.