Hydatid cyst or echinococcosis is caused by a Parasite which belongs to a sublass of cestodes. The adult form of this parasite is usually seen in the dog"s intestine and its larvae may develop in mammals like humans, sheep, cattle, goats, camels and horses. Humans are an intermediate host of this parasite. This cyst is chiefly found in the liver, and less frequently in the lungs. However, the CNS is very uncommon site. This article discusses a very rare case of development of this cyst in the cerebellum of an eight year old boy. This disease was left undiaognosed unitl aCT - Scan and MRI were performed. Hopefully, this article will bring into mind that hydatid cyst can be one of the differential diagnosis of a space taking lesion in the CNS.