Purpose. The purpose of this study was to evaluate the safety and efficacy of sonographically guided percutaneous drainage and irrigation of hepatic hydatid cysts.Methods. Sixty-one patients with 84 hepatic hydatid cysts were treated using the puncture, aspiration, injection, and reaspiration (PAIR) technique under sonographic guidance. Patients with cysts larger than 6 cm in diameter underwent PAIR followed by percutaneous drainage (PAIR-PD). The cysts were sterilized by the injection of 1 of 2 scolicidal agents, 20% hypertonic saline solution (38 patients) or 0.5% silver nitrate (23 patients). All patients underwent follow-up examinations for 1 month-6 years after aspiration. Clinical and radiologic examinations and laboratory analyses were performed every month for the first 6 months and then at 3-month intervals.