Of 2,130 consecutive patients admitted to two hospitals with acute brain infarction, we examined 11 patients (0.52%) with medial medullary infarction. The infarcts documented by MRI were unilateral in 9 patients and bilateral in 2 patients, and located in the anteromedial arterial territory of the upper or middle part of the medulla. Atherosclerosis of the vertebral arteries was the predominant vascular pathology. The vertebral artery was occluded at its terminal portion in 7 patients. Nine patients had hypertension, and 8 of these had additional risk factors. Male gender (10 patients) and smoking habits (7 patients) were more prevalent compared with patients with pontine infarction. One patient had a medial medullary infarction attributed to dissection of the vertebral arteries following blunt head injury. Limb weakness was the major symptom in all patients, and gaze-evoked nystagmus was also frequent (6 patients). Tongue weakness ipsilateral to the infarct, the classic sign of medial medullary syndrome, was evident in only 3 patients. The outcome was usually excellent.