Hydatid cyst (echinococcosis) is an endemic parasitic disease, usually encountered in those dealing with agriculture and livestock. The most frequently affected organs are the liver and the lungs. The disease is very rarely encountered in soft tissues. Diagnosing a soft-tissue hydatid cyst may be challenging unless the mass possesses the characteristic features of a hydatid cyst. Soft-tissue hydatid cysts may be treated percutaneously, just like those encountered in the liver. In this case report, we present the radiological findings and modified percutaneous aspiration-injection-reaspiration (PAIR) treatment of a hydatid cyst located in the posterior aspect of the thigh.