We divided eight patients with Sturge-Weber syndrome into two groups, depending on the presence or absence of clinical progression, and investigated differences in brain hemodynamics between the groups by measuring regional cerebral blood flow (rCBF) before and after acetazolamide activation using stable xenon computed tomography. The most evident difference between the groups was acetazolamide vaso-reactivity (delta CBF) in the primarily healthy area remote from lesion. delta CBF on the contralateral side and in distant areas on the affected side was significantly lower in the group with progression group (unpaired t-test), although both groups had similar delta CBF values in the area of primary lesion. This remote hemodynamic compromise might aggravate the clinical condition. Operations were performed on three patients with progressive disease, resulting in good seizure control with anticonvulsants and a variable degree of improvement in neurological symptoms and vasoreactivity. The neurological improvement appeared to correlate with the size of the resected area and the increase in delta CBF after surgery.