The authors report a case of convulsion during intra-arterial selective infusion of fasudil hydrochloride (FSD) for treatment of vasospasm following subarachnoid hemorrhage (SAH). A 47-year-old man (Hunt and Kosnik grade I) presented with sudden onset of headache and was diagnosed with SAH on CT, and admitted to our hospital. Digital subtraction angiography (DSA) performed on admission revealed an anterior communicating artery aneurysm. Neck clipping of the aneurysm was performed on the same day and no neurological deficits were noted postoperatively. Motor aphasia appeared on day 11 after the operation, and emergency DSA revealed vasospasm of the left middle cerebral artery and its branches. Emergency percutaneous transluminal angioplasty was performed with successful dilation of the left M1 artery, and 25 milligrams of FSD was injected into the left M1 artery selectively. During this injection, right hemifacial convulsion appeared, and three minutes later disappeared. No treatment was needed for the seizure. Additional injection of 30 milligrams of FSD into the left internal carotid artery resulted in vasodilatation of the left M1 artery and its branches, improvement of their blood flow on angiography, and recovery from motor aphasia. The patient was discharged 1 month later with no neurological deficits. Intra-arterial selective infusion of FSD plays an important role in treatment for vasospasm following SAH, however, we must be aware of risks of complications such as convulsion.