Symptomatic trigeminal neuralgia due to a brainstem infarction is said to be rare. However, facial pain is not uncommon in Wallenberg's syndrome. Facial pain related to a Wallenberg's syndrome may be either persistent of intermittent, and occasionally occurs in brief attacks. Here, we report a patient with a right lateral medullary infarction who started having first division trigeminal neuralgia 1 month after the stroke. The pain paroxysms were suppressed with gabapentin.