Between 1978 and 2002, 15 patients (mean age, 23.0 +/- 8.5 years) with cardiac and pericardial echinococcosis were treated surgically. The cysts were located in the right atrium in 3 patients, on the anterior myocardium in 7, and pericardially in 5. The 3 patients with right atrial cysts were operated on using cardiopulmonary bypass. There were 4 recurrences requiring re-operation after a mean of 12 months. All other patients received mebendazole treatment and exhibited no recurrence during follow-up. One late death due to chronic right heart failure occurred after 10 months of follow-up. The serologic test is an effective method of diagnosis in undeveloped and developing countries.