Percutaneous treatment of Hydatid Liver Cyst (HLC) with scolicidal agent under ultrasound guidance is now worldwide used after the advent of Percutaneous-Aspiration-Injection and Re-Aspiration (PAIR) and its modifications. Although HLC represent a benign disease, treatment has to be considered mandatory in symptomatic cysts and recommended in viable cysts because of the risk of severe complications. In this article, clinical indications, PAIR technique with results and complications are discussed. Finally, clinical flow-chart of active and inactive HLCs is reported. The present article is a review of some patents in the Hydatid liver cyst.