Association of migraine and tonic pupil has been reported very rarely. We reported a young female with symptoms of migraine who developed a mydriatic pupil in one of her attacks. The pupil was unresponsive to light with little response to near reflex. In 0.125% pilocarpine test affected pupil responded significantly and tonic pupil was diagnosed. The patient's problem became severe after a one-year follow up. We discussed possible mechanisms and reviewed previous cases with the same diagnosis. Evidences show that this association may be caused by infarction of parasympathetic fibers secondary to prolonged vasospasm which sometimes occurs in migraine.