Though rare, cardiac echinococcosis should be included in the differential diagnosis of cardiac tumors, particularly in patients originating from endemic areas or with manifestation of hydatid disease in other organs. Diagnosis and localisation of the cysts is best accomplished with non-invasive methods such as 2-D transthoracic and transesophageal echocardiography, computed tomography and NMR. Excision of the cardiac cyst from the interventricular septum in a 21 year old patient with polyvisceral echinococcosis was performed with cardiopulmonary bypass. Adjunctive medical therapy with mebendazol is being continued for 24 months postoperatively. Twelve months after surgery the patient is asymptomatic without echocardiographic signs of recurrence.