Here, we present a rare case of a hydatid cyst in a 25-year-old woman, mimicking a uterine leiomyoma. The patient was admitted with lower abdominal pain and tenesmus, and ultrasonographic examination revealed a 10×10 cm uniloculated mass with regular borders in the myometrium. The patient was operated with an initial diagnosis of a uterine leiomyoma with cystic degeneration, which was found to be hydatid cyst during frozen section and confirmed with the identification of protoscoleces during microscopy. This rare case report indicates the necessity of considering hydatid disease in the differential diagnosis of pelvic cysts, especially in endemic regions.