Hydatid disease of the liver is uncommon in the United States. Infection occurs when man becomes the accidental intermediate host for the Echinococcus organism. The life cycle of the organism, diagnosis, and preoperative evaluation of the patient is discussed. The operative technique used to safely evacuate a mature cyst is demonstrated. Although commonly described, excision of the intact cyst is not always possible. Careful evacuation and sterilization of the cyst must then be performed.