Echinococcal infection of the heart is rare. The preoperative findings, with special attention to two-dimensional echocardiography (2DE), of six patients with cardiac echinococcosis and their surgical and pathological correlations are reported. Cardiac hydatid cysts (HCs) were located in the cardiac apex in three patients, in the upper part of the interventricular septum extending towards the anterior aspect of the heart in one and in the postero-superior right atrial wall in another patient. The remaining patient had multiple intrapericardial cysts. In three patients the cysts presented as well defined, rounded, echolucent masses within the myocardial wall bulging into the cardiac chambers. In two patients, the cysts had ruptured into a cardiac chamber with loss of the characteristic 'cystic' appearance; these cysts presented as an echogenic or solid mass protruding into a cardiac chamber. Finally, another patient had one HC with echolucent appearance and another HC in a different location with echogenic appearance; this last cyst corresponded to a degenerated HC. In two cases the cyst showed a loculated internal aspect. In one patient the myocardial segment involved by the cyst had a dyskinetic movement. In all six patients, 2DE accurately demonstrated the location and morphological details of the cardiac cysts, permitted recognition of the ruptured and/or degenerated cysts and was superior to thoracic computed tomography and angiography in the preoperative assessment of these patients. Nuclear magnetic resonance imaging (one patient) gave no further information to that obtained by 2DE. We conclude that 2DE is the technique of choice for an early diagnosis of this rare entity.