Acute cerebellar ataxia (ACA) is an inflammatory CNS disease that is characterized by rapid onset of ataxia in a child under 6 years of age. Symptoms typically occur in association with a relatively benign viral illness and have been reported after vaccination as well. Immunological studies suggest that both involve autoimmune destruction of axon tracts, with pathological and radiographic evidence of a link with multiple sclerosis. The emergency approach should be focused on excluding more significant illnesses, such as meningitis or an intracranial mass lesion. Here we present a case of a young girl with ACA and review the relevant literature.