OBJECTIVES: This study aims to clarify the association between alcohol intake and stroke severity at admission and discharge according to sex and stroke subtype in Japanese patients with acute stroke. MATERIALS AND METHODS: We analyzed the data of 199,599 patients registered in the Japan Stroke Data Bank from 1999 to 2018, including sex, age, stroke subtypes (cardioembolic ischemic, noncardioembolic ischemic, hypertensive hemorrhagic, nonhypertensive hemorrhagic, and subarachnoid hemorrhagic), dates of onset and admission, National Institutes of Health Stroke Scale score at admission, modified Rankin Scale score at discharge, and alcohol intake. Multivariable logistic regression analysis adjusted for stroke-related factors was performed to estimate the odds ratios of alcohol intake for stroke severity. RESULTS: In cardioembolic ischemic stroke, a significant protective effect of moderate intake on severity at admission was observed in both sexes. In noncardioembolic ischemic stroke, a significant protective effect on stroke severity at admission was found for each sex. At discharge, the results also showed a significant protective effect for each sex with moderate intake. For both subtypes of ischemic stroke, a J-shaped relationship between alcohol intake and stroke severity at admission and discharge was observed in women and men. In hypertensive hemorrhagic stroke, a significant protective effect was found in men at both admission and discharge. In women, heavy drinking had a significant harmful effect on stroke severity at admission. CONCLUSIONS: Habitual alcohol intake is associated with stroke severity at admission and discharge regardless of sex.