Acute transient vertigo, ataxia, and hypertension after trigeminal nerve block via a coronoid approach with alcohol have been reported previously. We report a similar complication after the same block with nerve stimulator guidance with bupivacaine without alcohol. Stimulation of the vestibular canal by the needle, or disturbance to its blood supply, presence of an abnormal anatomical connection of the mandibular nerve and vestibular system or spasm of cerebellar arteries from the stimulating needle are possible causations rather than the drug used, whether it is alcohol or bupivacaine. Awareness of such rare but serious complications is important, and radiological-guided interventional treatment may minimize such complications.