Unlabelled: Acute cerebellitis is usually infectious, post-infectious or post-vaccination. Rarer causes include toxic ones. The clinical presentation is usually benign, however, severe cases with brainstem compression may present as coma. Regarding three pediatric clinical cases, the authors make a brief review on this entity, with particular emphasis on its causes and imaging findings. Case Reports: Three cases of pediatric acute cerebellitis are presented- post-viral, after acute intoxication with carbon monoxide and after accidental ingestion of methadone. Discussion: The etiopathogenic mechanisms underlying the imaging changes found in each of the three cases presented are discussed. Conclusion: An imaging examination confirms the diagnosis of cerebellitis and is important to monitor severe cases. MR is more sensitive than CT in the evaluation of the cerebellar parenchyma.