Hydatid disease is caused by the larval stage of dog tapeworm, Echinococcus granulosus. It is endemic in many regions of the world. Liver and lung are the common organs affected by hydatid disease. The peritoneal hydatid disease is rare. In most of these cases the peritoneal involvement is related to previous surgery for hepatic hydatid disease. In some cases it may be related to traumatic rupture of a hepatic or a splenic hydatid disease. However primary peritoneal involvement without involvement of any other organ in the body is very rare. A case of primary peritoneal hydatid cysts filling the cavity of the abdomen and pelvis without any other organ involvement is presented and discussed.