Objective: The term “Ataxia” is used to denote disturbances of the body posture and its movement that are normally controlled by the cerebellum. frontal lobes and the posterior columns of the spinal cord. The initial symptom and the most prominent feature of ataxia is abnormal gait which is characterized by lurching and wide base walking. Knowing that, the acute ataxia is among those problems that brings very soon the child to pediatrics neurology department and in view of lack of any survey in this neid in our country, we decided to investigate the etiology of acute ataxia in Islamic Republic of Iran.

Materials & Methods: Our patients were recruited from 100 children who were brought to neurology service of Mofid children hospital with the chief complaint of acute ataxia over 2 years period. (sep 2001 to sep 2003). All of those 100 patients were admitted and required investigations were performed.

Results: Results of our workup revealed that the most common cause of acute ataxia is acute cerebellar one, which all of them preceded by viral febrile illness. The second frequent cause of acute. Ataxia is due to drug intoxication, which commonly was observed between 2 – 4 years period.

Conclusion: The remaining etiologies in descending frequency were as follow, Infectious polyneuropathy, Migraine, Opsoclonus – Myoclonus, Brain tumor, ADEM,MS and Epilepsy.