BACKGROUND: Cerebellar infarction is an uncommon but serious cause of isolated acute vestibular symptoms, particularly in young, healthy individuals, and can easily be overlooked. We present two cases of cerebellar infarction in U.S. Air Force pilots, one of which occurred during flight.CASE REPORTS: A 41-yr-old man developed acute vertigo, disequilibrium, nausea, and headache, with progressive slow symptomatic improvement, and presented to medical attention 4 d after symptom onset. Brain magnetic resonance imaging showed right inferomedial cerebellar infarction. Echocardiography discovered patent foramen ovale and atrial septal aneurysm. A 40-yr-old man developed severe vertigo, nausea, and vomiting during initial aircraft descent. Head computed tomography scan was performed acutely and was normal. Initial assessment was benign paroxysmal positional vertigo. Brain magnetic resonance imaging 1 mo after symptom onset showed a small right inferior cerebellar infarction. Patent foramen ovale and bilateral atrial enlargement were seen on echocardiography. Both pilots made full neurological recoveries and were eventually returned to flight status.DISCUSSION: Central causes of isolated acute vestibular symptoms are uncommon and are often not considered in otherwise healthy individuals. Cerebellar infarction is one of these uncommon but increasingly recognized causes of acute vestibular symptoms. As evaluation and management of central causes are much different from peripheral conditions, prompt localization confirmation is paramount. Accurate evidence-based bedside screening methods are available for rapid localization. Awareness of the possibility of central etiologies and careful clinical evaluation with application of bedside screening methods in patients with acute vestibular symptoms will reduce the number of inaccurate diagnoses.Hesselbrock RR. Cerebellar infarction presenting with acute vestibular syndrome in two U.S. Air Force pilots. Aerosp Med Hum Perform. 2017; 88(9):880–883.