We report two cases of cystic echinococcosis at unexpected locations. Patients were a 64-year-old man and 35-year-old woman. A cystic mass was incidentally found between the prostate and seminal vesicles in the male patient, using ultrasonography during a check-up for ischemic coronary disease. The female patient was admitted to the hospital with symptoms of cardiopulmonary disease, but her detailed radiological examination showed a cystic lesion in the interventricular septum of the heart. Both patients were operated, and examinations of the histologic sections revealed cyst walls consistent with echinococcal infection. Attention should be focused on this entity even in endemic areas, and pathologists should be aware of the histologic characteristics of this lesion, to avoid misdiagnosis as a nonspecific cyst.