We studied 13 patients with supranuclear lower cranial nerve ("pseudobulbar" or "suprabulbar") palsy of acute onset. While seven patients had had a prior stroke, six patients had no history of stroke. Eight patients experienced a complete bilateral supranuclear lower cranial nerve palsy, which was isolated in five patients and associated with hemiplegia and with hemiparesis in three patients. Pseudobulbar palsy was partial in five patients. Only one patient had neuropsychologic impairment. The pseudobulbar features improved or recovered within a few weeks in all patients. The common characteristic of the lesions on computed tomography or magnetic resonance imaging was the interruption of the corticonuclear pathways contrasting with marked sparing of the corticospinal pathways in both hemispheres. These lesions were either an opercular infarct, or a deep infarct in the corona radiata or internal capsule, or a lenticular hemorrhage. Hypertension was the most prevalent concomitant. Our findings suggest that acute pseudobulbar or suprabulbar palsy has rather stereotyped anatomic-vascular correlates and time course.