Cardiac hydatic cysts are rare and represent 0.5 to 2% of all hydatic cysts in humans [1, 2]. They are usually found in the left or right ventricle, and exceptionally in the interventricular septum. An exclusively pericardia hydatic cyst is excessively rare. The case reported here emphasizes: That this hydatid cyst of the pericardium remained asymptomatic until rupture. The role of echocardiography as a diagnostic tool. The superiority of MRI to CT Scan in the establishment of a precise preoperative diagnosis.