A Chinese adult with Churg-Strauss syndrome with prominent cardiac involvement is described. The myocardial impairment initially showed good response to corticosteroid and cyclophosphamide. However, the cardiac status deteriorated later despite the absence of disease activity elsewhere. Endomyocardial biopsy was performed to determine the possibility of isolated myocardial relapse in case additional immunosuppression would be beneficial. Histology of the endomyocardial biopsy revealed myocardial fibrosis. Since cardiac involvement is the major cause of mortality in this condition and delayed treatment can lead to intractable cardiac failure, we advocate that endomyocardial biopsy should be performed more liberally and possibly serially to assess the disease activity in the myocardium. Immunosuppression may then be adjusted. To our knowledge, the occurrence of Churg-Strauss syndrome in Chinese has not been reported in the English literature.