We sought to prospectively assess the feasibility and in-hospital efficacy of the PercuSurge GuardWire temporary balloon-occlusive system for neuroprotection during carotid angioplasty and stenting (CAS).Carotid angioplasty and stenting harbors a risk of distal embolization. Cerebral protection devices are currently under clinical investigation.Ninety-six consecutive patients with carotid bifurcation disease underwent a total of 102 CAS procedures with the intention to use the GuardWire for neuroprotection. GuardWire deployment was achieved in 99 procedures performed in 93 patients (97%). Device failure (n = 3) and severe neurologic responses to balloon occlusion of the targeted carotid artery (n = 2) accounted for five additional procedures that were essentially concluded without neuroprotection, for a total of 94 procedures completed as intended in 88 patients (92% procedural feasibility rate). Carotid angioplasty and stenting was performed successfully in 94 patients (100 procedures). There were no in-hospital deaths; but three patients (3.1%) sustained strokes, and two patients experienced transient ischemic attacks, for a total periprocedural complication rate of 5.2%. One major stroke occurred with the GuardWire in place, whereas two minor strokes were observed in patients in whom the device could not be deployed. Thus, successful neuroprotected CAS without major neurologic events was achieved in 87 patients (91%). The GuardWire temporary balloon-occlusive system is feasible as an adjunct to CAS in the majority of patients. It is associated with a 3.1% rate of major periprocedural neurologic complications. Adverse neurologic reactions to balloon occlusion may prohibit effective use of the system in about 2% of patients.