Hydatid cyst disease is a zoonotic disease caused by Echinococcus granulosus, E.multilocularis or E.Vogli. The most common primary site is liver (75%) followed by lungs (5-15%) and other organs constitute 10-20%. Peritoneal hydatid cysts are very rare especially primary peritoneal hydatid. Secondary peritoneal hydatid cysts are relatively common, which usually occurs due to rupture of primary hepatic hydatid cyst. We present a rare case of large primary peritoneal hydatid cyst misdiagnosed as torsion of ovarian cyst that underwent Laparotomy with cyst excision and postoperative Albendazole therapy.