Hydatid cyst is a parasitic disease caused by the tapeworm Echinococcus granulosus. Hydatid cyst disease mostly involves the liver and the lung, while renal involvement is rare, comprising only 2% of all cases. An interesting case of a giant renal hydatid cyst is presented in our first case. The big cystic mass detected at ultrasonography (US) and computerized tomography (CT) in a 44-year-old female looked like a simple cyst. No germinative membrane or any other radiological sign of a hydatid cyst was present. An another interesting case of a giant renal hydatid cyst is presented in our second case. A 27-year-old female admitted to the hospital with the complaint of right flank pain for three years and for a pain in right gluteal region for a year. Abdominal computed tomography revealed two cysts in right kidney 12x12 cm and 5x5 cm in size. Also a cyst between internal and external oblique muscles 5x5 cm in size, and a cyst in the right gluteal region 12x12 cm in size. Despite modern imaging methods, isolated renal hydatid disease might still cause diagnostic dilemma and hydatid cysts can be found in unusual localization. Key words: Echinococcus, hydatid, kidney.