Background and Purpose— Migraine with aura is associated with ischemic stroke, but few studies have investigated the clinical and anatomic features of this association. We assessed the association of probable migraine with and without visual aura with ischemic stroke within subgroups defined by stroke subtype, vascular territory, probable migraine characteristics, and other clinical features. Methods— Using data from a population-based, case-control study, we studied 386 women ages 15 to 49 years with first ischemic stroke and 614 age- and ethnicity-matched controls. Based on their responses to a questionnaire on headache symptoms, subjects were classified as having no migraine, probable migraine without visual aura, or probable migraine with visual aura (PMVA). Results— Women with PMVA had 1.5 greater odds of ischemic stroke (95% CI, 1.1 to 2.0); the risk was highest in those with no history of hypertension, diabetes, or myocardial infarction compared to women with no migraine. Women with PMVA who were current cigarette smokers and current users of oral contraceptives had 7.0-fold higher odds of stroke (95% CI, 1.3 to 22.8) than did women with PMVA who were nonsmokers and non–oral contraceptive users. Women with onset of PMVA within the previous year had 6.9-fold higher adjusted odds of stroke (95% CI, 2.3 to 21.2) compared to women with no history of migraine. Conclusions— PMVA was associated with an increased risk of stroke, particularly among women without other medical conditions associated with stroke. Behavioral risk factors, specifically smoking and oral contraceptive use, markedly increased the risk of PMVA, as did recent onset of PMVA.