Superficial temporal artery-middle cerebral artery(STA-MCA)bypass surgery is a common operation in neurosurgery. There are several variations of this surgical method. We conducted a questionnaire survey on the details of surgical procedures in 171 neurosurgical institutes in Japan. Contrary to expectations, wide variations emerged in some surgical procedures, including the shape of skin and muscle incisions, the site of the temporary clip at the donor artery(STA), and the cutting method of the donor end. Western Japan institutions tended to vary more in terms of skin incision methods and donor cutting methods. It will likely be useful in the future to be aware of the numerous variations in surgical methods.