The authors’ 15-year experience with migraine surgery has led them to believe that the most common reasons for incomplete response are failure to detect all of the trigger sites or, on rare occasions, inadequate surgery on the trigger sites. Thus, accurate identification of trigger sites is essential. The purpose of this article is to share the authors’ current stepwise algorithm for accurately detecting the migraine trigger sites, which has evolved through surgery on nearly 1000 patients. To begin, a thorough history is taken. Each patient’s constellation of symptoms can point toward one or multiple trigger points. The patient is asked to point to the most frequent site from which migraine headaches originate with one fingertip, and then the site is explored with a Doppler. If an arterial Doppler signal is identified at the site, it is considered an active arterial trigger site. Response to a nerve block with a local anesthetic in a patient with an active migraine headache confirms the presence of a trigger site. If the patient does not have pain at the time of the office visit, an injection of botulinum toxin A at the suspected trigger site may be considered. Although positive responses to botulinum toxin A and nerve block are very helpful and reliable in confirming the trigger sites, negative responses must be interpreted with extreme caution. In patients with a migraine headache starting from the retrobulbar site, a computed tomography scan of the paranasal sinuses is obtained to look for contact points and other pathology that would confirm rhinogenic trigger sites.