Summary: Extracranial-intracranial (EC-IC) bypass is one of the most fundamental techniques for cerebrovascular surgery. We describe our surgical results and strategy for performing the EC-IC bypass safely and precisely in patients with chronic stage ischemia. Surgical indications were decided for symptomatic internal carotid or middle cerebral artery occlusive disease with misery perfusion detected using quantitative single-photon emission computed tomography. Antiplatelet medications were continued, and intravenous hyperosmotic colloid infusion was started 1 week before operation.Target recipient M4 arteries were superimposed on the superficial temporal artery and cranial bone.Preparation of the superficial temporal artery was performed by using an ultrasound instrument (Harmonic Scalpel ® ). The craniotomy site was located under the supratemporal line. Various anastomotic techniques were adopted, including continuous, running, and intermittent suturing methods. The second target recipient artery was confirmed using intra-arterial indocyanine green videoangiography.