Hydatid diesease (HD) is a parasitic disease that is most commonly caused by the larval stage of Echinococcus granulosus. It is still a severe public health problem in the world and most commonly involves the liver and the lungs. However, HD can occur in almost any part of the body. Isolated omental hydatid cyst is one of the least common sites. Information about the appearance of cysts within the omentum is limited because of their extremely rare occurrence. In the evaluation of HD, clinical findings, serologic tests, and imaging methods such as plain radiography and ultrasonography are useful. This report describes the clinical, radiologic, and pathologic findings of omental hydatid cyst in addition to a literature review. © 2009 Elsevier Inc. All rights reserved.