Cystic echinococcosis, or hydatidosis, is a parasitic disease caused by the larva of the Echinococcus granulosus (E. granulosus). The liver is the most frequent location of echinococcal cysts. Imaging of the liver is important for the diagnosis, the evaluation of the treatment, and also for the detection of complications. Many classification systems exist, and the ultrasound is the main radiological modality these systems are based on but with the advances in other cross-sectional imaging modalities such as computed tomography and magnetic resonance imaging have started playing an increasing role in diagnosis and management of these patients, including various complications. Alveolar echinococcosis is caused by another cestode in the same genus, Echinococcus alveolaris (E. alveolaris), with different biological behavior, mimicking a malignant mass due to its invasive growth pattern, diagnosed mainly with cross sectional imaging.