Secondary peritoneal hydatidosis is caused by spontaneous or iatrogenic rupture of hepatic echinococcal cysts. We describe the case of a 65-year-old Tunisian male patient with previous history of liver hydatidosis who presented to our attention with subocclusive status. Imaging revealed a retrovesical hydatid cyst, adherent to the sigmoid colon. The treatment of choice was surgical removal of the cyst and the sigmoid colon. The patient is now being closely followed up.