Transcranial Doppler ultrasound (TCD) findings are described in a patient with acute thrombosis of the sagittal venous sinus. The TCD finding of prominent venous signals adjacent to the middle cerebral artery gave the first indication of the diagnosis, which was subsequently confirmed by computerized tomography. Awareness of the possible TCD findings in patients with a similar history may lead to a more rapid diagnosis of cerebral venous sinus thrombosis.