Due to the great variety of clinical classification systems and syndromes, a representative overview of the etiology and prognosis of brain stem infarctions is missing. From the German Stroke Data Bank we therefore investigated 455 patients with visible brainstem infarction on cerebral imaging in comparison to patients with other infarct localizations. Follow-up after 3 and 12 months assessed functional outcome and recurrence of cerebral ischemia. Of 455 patients with acute brainstem infarction, 115 had additional infarctions in other vascular territories. In the remaining 340 patients with isolated brainstem infarction, the classification was: small vessel disease in 36.2%, macroangiopathy in 22.6%, and cardioembolism in 11.2%. After 3 months, 10% of the patients with isolated brainstem infarction had died and 55.6% were functionally independent. Mortality was 43.5% in patients with combined brainstem infarction. Our study highlights the frequency of small vessel disease as well as the relatively favorable prognosis in isolated brainstem infarction and preserved consciousness.