Moyamoya syndrome is a vaso-occlusive disease involving the intracranial vessels of the circle of Willis which is accompanied by an intense compensatory recruitment of new vessels. Angiogenic substances such as basic fibroblast growth factor (bFGF) present in the cerebrospinal fluid (CSF) have been proposed as possible mediators of the neovascular response. We analyzed CSF samples collected intraoperatively from predominantly pediatric patients with moyamoya and other conditions such as Chiari malformation (Ch), tethered cord (TC), arteriovenous malformation (AVM), brain tumor (BT) and hydrocephalus (HCP). We found that CSF bFGF was significantly elevated in patients with moyamoya (141 pg/ml, n = 37), Ch (56.7 pg/ml, n = 22), TC (55.1 pg/ml, n = 23), AVM (354 pg/ml, n = 5), and BT (208 pg/ml, n = 5) compared to patients with HCP (5.5 pg/ml, n = 7) and controls (1.6 pg/ml, n = 25; p < 0.05). There was no dependence of CSF bFGF on patient age or gender. Although CSF bFGF in the moyamoya group showed no correlation with the Suzuki radiographic stage at either pre- or post-operative (1-year follow-up) angiography, it showed a trend with the Matsushima angiographic score with increasing collateral vascularization from the synangiosis developing at higher levels of CSF bFGF. Our findings suggest that CSF bFGF may be playing a wide-ranging role in a number of central nervous system conditions associated with ischemia and hypervascularity. Although not a specific marker for moyamoya, elevated CSF bFGF may serve as a weak predictor of the extent of angiogenesis to be expected in indirect revascularization procedures.