The trigeminal artery (TA) is the most common embryonic carotid-vertebrobasilar anastomosis to persist into adulthood. It typically extends from the internal carotid artery to the basilar artery. Persistent primitive arteries are usually found incidentally, but are often associated with vascular malformation, cerebral aneurysm and, in case of TA, with trigeminal neuralgia. We present one patient with TA as a cause of trigeminal neuralgia and in other three as an incidental finding, on TC and MR angiograms.