We described the techniques and efficacy of intra-arterial papaverine hydrochloride infusion (IA-PAP) for symptomatic vasospasm due to aneurysmal subarachnoid hemorrhage based on our experience and review of the literature. Angiographic improvement occurred almost always, but only 50% of patients who presented with acute symptoms showed remarkable clinical improvement after the first, second, or third IA-PAP. Recurrent vasospasm after IA-PAP frequently occurred and this seems to be an apparent source of controversy regarding its efficacy. Review of the literature indicates that IA-PAP may be most effective in combination with percutaneous transluminal angioplasty. Further controlled studies should be conducted regarding papaverine''s true efficacy including most effective papaverine concentration and rate of infusion, maximum total dose, site of infusion, timing of treatment, and selection of patients.