The distribution pattern of cerebral blood flow (CBF) was evaluated in 13 children with moyamoya disease after revascularization. Combined surgery involving encephaloduroarteriosynangiosis and encephalomyosynangiosis was performed in 21 hemispheres. CBF was assessed by dynamic imaging using N-isopropylp[123I]iodoamphetamine-single photon emission CT (IMP-SPECT) at 46 months on average after revascularization. None of the patients suffered recurrent ischemic attacks after the bilateral combined surgery, and 62% showed excellent active daily life. However, 70% showed poor school performance with impaired cognitive function. Although the superficial temporal artery was dilated in follow-up angiograms, the revascularized area was confined to the craniotomy field. CBF images disclosed a low-perfusion state with a noninfarcted ischemic pattern in 71% of the revascularized hemispheres, especially in the frontal lobe. These findings show that although potentially beneficial effects can be expected following revascularization, it should be recognized that, in most patients, increased blood flow is gained only in a limited area around the surgical field. For patients who show progressive reduction of regional CBF, additional revascularization procedures are recommended.