A 1-year and 11-month-old girl with congenital mitral stenosis (MS) and patent ductus arteriosus (PDA) underwent mitral valve replacement (CarboMedics 16 mm) and ligation of PDA. Though she had suffered from severe postoperative pulmonary hypertension crisis, the inhalation of nitric oxygen (NO) with intravenous use of phosphodiesterase (PDE) III inhibitor and prostaglandin I2 (PGI2) was useful for the postoperative management. Severe pulmonary hypertension is the one of critical postoperative complications for congenital MS with PDA cases. Therefore adequate treatments, such as the combination of NO, PDE Ill inhibitor and PGI2, should be important for those cases. In our case, cardiac catetherization revealed a remaining of pulmonary hypertension under medication of beraprost sodium. Further observation should be necessary for the patient including new medicine, such as sildenafil citrate.