**Abstract**

Hydatid disease is a widely common parasitic disease caused by the species; *Echinococcus granulosus* and *Echinococcus multilocularis*. Echinococcosis is a serious medical, economical and social handicap all over the world. Almost any organ of the body can be involved with the zoonosis, liver and lungs are the most frequently involved organs. Imaging has a critical role for diagnosis of the disease. Radiography is the first imaging tool. Although CT aids the detection of size, number, location and imaging of local complications for diagnosis of hydatid cysts, sometimes atypical lesions rise in the imaging tools. MRI may help for differentiation of hydatid lesions from other neoplastic and hypodense infective lesions. MRI is also better for biliary and neurological involvement. Ultrasound is especially helpful for abdominal hydatidosis and peripheral lung lesions. Regarding that clinical evaluation is difficult for hydatidosis; radiological findings should be evaluated well for accurate diagnosis. This chapter will focus on imaging of echinococcosis.

**Keywords:** *Echinococcus*, MRI, CT, USG, hydatid cyst
