Acute childhood ataxia is a common cause of presentation to the pediatric emergency room or child neurologist. The primary concern on initial assessment is to exclude serious causes of this clinical syndrome, including central nervous system infections and mass lesions, while recognizing the essentially benign nature of acute ataxia in most children. Childhood ataxia can be diagnostically approached by consideration of the temporal course and presence or absence of associated neurologic abnormalities. In all forms of childhood ataxia, outcome is largely determined by etiology. In this review, the various causes and syndromes of acute ataxia in childhood are described, with discussion of diagnostic considerations and an approach to investigation, treatment, and prognosis.