Hydatid disease, which is caused by the parasite Echinococcus granulosis, is endemic in certain parts of the world in which humans and sheep live in proximity. Hydatid cysts occur most often in the liver, and affliction with multiple cysts is rare. We present the case of a 48-year-old woman with 55 hydatid cysts (47 in the liver, 5 in the right lung, and 3 in the left lung). The cysts in the right lung were intact, and those in the left lung had ruptured. A partial cystectomy was performed to excise 34 cysts through a right thoracoabdominal incision. The remaining deeply seated cysts were treated by needle aspiration and the ultrasonographically guided injection of hypertonic saline. This case report indicates that open surgery accompanied by ultrasonographically guided aspiration can effectively treat multiple hydatid cysts in a single laparotomy session.