Abstract: AIM　To determine whether ONO-1078 pranlukast, 4-oxo-8-［p-(4-phenylbutyloxy) benzoyl-amino-2-(tetrazol-5-yl)-4H-1-benzopyran hemihydrate, a potent leukotriene antagonist, has protective effect on focal cerebral ischemia in mice. METHODS　Focal cerebral ischemia was induced by permanent middle cerebral artery (MCA) occlusion in mice. ONO-1078 (0.01, 0.05, 0.10 mg·kg^-1), dexamethasone (0.5 mg·kg^-1), nimodipine (0.2 mg·kg^-1) or saline (control) were injected ip once daily for 3 days, and 30 min before MCA occlusion. Twenty-four hours after cerebral ischemia, the neurological scores were evaluated, infarct volumes and areas of the right and left cerebral hemispheres were measured by computer imaging analysis. RESULTS　ONO-1078, dexamethasone and nimodipine reduced the neurological scores. ONO-1078 and dexamethasone reduced the ratio of right/left hemisphere area, indicating inhibition of brain edema, while nimodipine showed no effect. ONO-1078 dose-dependently reduced infarct size, and dexamethasone and nimodipine showed the same effect. CONCLUSION　ONO-1078 showed protective effect on focal cerebral ischemia. This may represent a novel approach to the treatment of acute cerebral ischemia.