By using a composition for preventing onset and/or recurrence of stroke which contains ethyl icosapentate as its effective component, onset and/or recurrence of stroke is prevented, or in particular, the onset and/or recurrence of stroke in a hyperlipidemia patient who has been treated with HMG-CoA RI, or in particular the recurrence of stroke in a patient who is beyond six months after the onset of stroke, is prevented.