Erdheim-Chester disease (ECD) is a non-Langerhans histiocytosis affecting multiple organs. Stroke as symptom onset of ECD with intracranial vasculitis is unusual. We report the case of a 64-year-old man who presented with an acute ischemic stroke associated with a moderate leukoencephalopathy and intracranial arteries stenosis. Four years later, he developed movement disorders with dysarthria and cognitive impairment. Neuroradiological findings demonstrated a rapidly progressive and diffuse leukoencephalopathy associated with brain atrophy and infiltration of the intracranial vertebral artery wall. Brain postmortem evaluation confirmed the diagnosis of ECD. This diagnosis should be evoked in patients with cryptogenic stroke, progressive leukoencephalopathy, and infiltration of the arterial wall.