Six patients with hydatid cysts of the heart have undergone successful enucleation of the cysts with the aid of cardiopulmonary bypass. Various locations of the cysts and their consequences are discussed in detail. The findings have been confirmed by clinical, radiologic, electrocardiographic, echocardiographic, cardiac catheterization, cardioangiographic, and coronary angiographic studies. All patients are in good condition. Length of follow-up is reported.