A 30-year-old man with bronchial asthma complained of horizontal diplopia. Partial oculomotor nerve palsy with restrictions of elevation and adduction, and mydriasis was observed in the left eye. Cranial magnetic resonance imaging demonstrated an infarct lesion in the territory of the left superior median mesencephalic branch of the posterior cerebral artery. Based on bronchial asthma, hypereosinophilia, mononeuropathy multiplex, pulmonary eosinophilia and positive perinuclear antineutrophil cytoplasmic antibody in the serum, the patient was diagnosed as having Churg-Strauss syndrome. This is the first case of oculomotor nerve palsy due to midbrain infarction associated with Churg-Strauss syndrome.