Headache is a common symptom at the onset of acute ischemic cerebrovascular disease. Simultaneous development of migraine-like headache and stroke in the same patient makes it difficult to differentiate between migraine-induced stroke and migraine-like headache attributed to ischemic stroke. We report a case of a 34-year-old woman with no previous migraine history who presented with migraine-like headache, thought to be a first attack of migraine, and who developed brainstem infarction shortly after triptan administration. Magnetic resonance imaging revealed an acute pontine infarction, and CT angiography revealed occlusion of the basilar artery. A detailed etiological evaluation revealed no risk factor for ischemic stroke. We believe that the migraine-like headache was the first symptom of cerebral ischemia and that sumatriptan accelerated the development of the infarction. This case report emphasizes the importance of accurate diagnosis of migraine before using triptans. Secondary causes of migraine-like headache should be excluded, especially in patients with migraine-like headache for the first time.