Four consecutive patients with subarachnoid hemorrhage were studied by serial cranial CT and transcranial Doppler ultrasonographic recordings. Patients were in the age range 52 to 67 years. According to Hunt and Hess scale the clinical status varied between grade I and IV. Increase in intracranial pressure "masked" the hemodynamic signs of cerebral vasospasm, reappeared after normalization of intracranial pressure following therapeutic management. Based on the reported findings transcranial Doppler ultrasonography should be considered an indispensabile diagnostic procedure however inadequate for monitoring the natural history of vasospasm complicated by intracranial hypertension.