Background: Hydatid disease, caused by Echinococcus granulosus, is a common parasitic infection of the liver between the human and animals and can be associated with different clinical manifestations and increased risks of several serious complications. There are rare reports on the isolated pelvic hydatid cyst without other organ involvement.

Case Report: A 16-year-old boy is presented with the primary complaint of consistent abdominal and pelvic pain. Pelvic sonography demonstrated a cystic mass in the pelvic region. Cystic mass contained the internal free wall with no solid components and compression on surrounding tissues. On imaging the evidence of cystic lesion with no similar cystic lesions were found in the liver, lungs and other body organs. Cystic mass was surgically removed and the pathological examination confirmed the diagnosis of a hydatid cyst.

Conclusion: Since the blood flow leaving small intestine and colon passes through the liver, it is considered as the most common site of hydatid cyst and isolated pelvic hydatid with no liver involvement is very rare. Surgery is offered for definitive diagnosis and treatment of hydatid cyst.