Background and aims Idiopathic hypereosinophilic syndrome, a rarely seen systemic disease, may cause cardiac valvular lesions by eosinophilic infiltration. This report describes management of a 25-year-old woman with idiopathic hypereosinophilic syndrome, severe mitral stenosis, and pulmonary arterial hypertension. Methods The patient was presented with haemoptysia and dyspnea on exertion. Echocardiography showed severe mitral stenosis and pulmonary arterial hypertension. Results After hematological stabilization, she underwent mitral valve replacement using a No. 27 bovine pericardial valve. In the intensive care unit she had a pulmonary hypertensive crisis, which ameliorated gradually with sedation and nitroglycerin. She was extubated and discharged on the second and seventh days, respectively. Conclusion Surgical experience for the patients with mitral dysfunction caused by idiopathic hypereosinophilic syndrome is limited. When mitral valve replacement is needed, the ideal type of prosthesis remains unclear and the presence of pulmonary arterial hypertension further complicates the management. We think that bioprosthetic valves would be the appropriate choice in eosinophilic mitral dysfunction requiring valve replacement.