The authors present an unusual case of intra-axial oculomotor nerve involvement due to midbrain infarction. The 65-year-old male patient presented with unilateral complete blepharoptosis and slight limitation of upgaze. Neurological examination revealed a complete ptosis of the left eyelid, slight limitation of elevation in the left eye, bilateral dysmetria and gait ataxia. Magnetic resonance imaging showed an acute infarction in the left paramedical part of the midbrain tegmentum, inferior to the left red nucleus, and a chronic infarction of the left cerebellum. Previous models for arrangement of oculomotor fascicle suggest a lesion involving the most caudal fibres for levator palpebrae and superior rectus, without affecting other extraocular muscles and pupillomotor fibres, is the most likely aetiology. This unusual case is important for further understanding of the topographic model of the oculomotor fibres in the midbrain.