OBJECTIVE Thromboembolism is one of the most common and serious complications associated with the endovascular embolization of intracranial aneurysms. We report our clinical experiences with intra-arterial tirofiban infusion during aneurysm embolization. METHODS The clinical, radiological, and laboratory data of 24 patients harboring 25 aneurysms (25 procedures) who underwent intra-arterial tirofiban infusion for thromboembolism during the endovascular treatment of intracranial aneurysms were reviewed retrospectively. Thrombi or emboli were resolved by superselective intra-arterial tirofiban infusion via a microcatheter. RESULTS The study cohort comprised 14 unruptured and 11 ruptured aneurysms. Intra-arterially infused tirofiban doses ranged from 0.2 to 1.0 mg (mean +/- standard deviation, 0.64 +/- 0.25 mg). Thromboemboli were resolved, and arteries were recanalized on all occasions except one: a case of distal middle cerebral artery embolism. No hemorrhagic complications related to intra-arterial tirofiban infusion occurred. CONCLUSION Intra-arterial tirofiban delivery appears to be a safe and effective treatment modality when thromboembolism is encountered during the endovascular treatment of intracranial aneurysms.