A 13-year-old girl presented with a 1-month history of progressive exertional dyspnea (NYHA class Ⅳ) and exophthalmos for 6 months. She had a history of long-standing asthma and the presence of allergy. Hypereosinophilia and increased serum IgE levels (2 472 IU/mL) were observed. Chest radiography and a high resolution CT scan documented a massive interstitial pulmonary infiltration. Echocardiography confirmed mild tricuspid regurgitation, apical obliteration of the right ventricle by fibrocalcific thickening of the endocardium and echogenic material suggestive of thrombosis. Churg-Strauss syndrome with cardiac involvement (endomyocardiopathy) was diagnosed. The patient received anticoagulation and corticosteroid therapy. In view of rapidly progressive severe endomyocardiopathy and stable hematology, the patient was referred for cardiac surgery. Histopathological examination of resected specimens confirmed laminated thrombus but without any trace of eosinophils embedded.