The persistent trigeminal artery (PTA) is the most common fetal carotid-basilar anastomosis which may persist into adult life. In the literature there are numerous papers referring to the anatomical characteristics of this anomalous vessel. In the majority of cases PTA is an incidental finding and its clinical significance has been debated. Some authors describe the coincidence of PTA with various clinical syndromes. However, there are few reports linking PTA with the symptoms of vertebrobasilar insufficiency. We present a patient with a 3-year history of recurrent dizziness and impaired vision, precipitated by physical activity, in whom neuroimaging techniques revealed a persistent left trigeminal artery (PTA). In our case the occurrence of PTA might have been related to the clinical manifestation and the potential mechanism will be discussed.