RESUMEN
INTRODUCTION: Echinococcus granulosus is a parasitic tape worm. The definitive host is the dog and humans are one of its intermediate hosts. It involves organs such as liver and lungs. Uterus involvement is very rare. PRESENTATION OF CASE: We here report a case of primary uterus hydatid cyst that we had to remove her uterine on left ovary and fallopian tube. Generalized toxic shock and infection due to cyst rupture or organ dysfunction due to invasion (like our patient) or pressure of cyst are complications of this cyst. DISCUSSION: Because of low incidence of hydatid cysts in uterus it can be misdiagnosed by mimicking other conditions such as multi-cystic ovarian tumor, hemorrhagic ovarian cyst, endometrioma, cystadenoma, leiomyoma and etc. CONCLUSION: Especially in endemic area for this parasite, one of differential diagnoses of pelvic cyst must be echinococcosis.