This case report concerns a 22-year-old woman with large patent ductus arteriosus and atrial septal defect. She was referred to our hospital because of exertional dyspnea and was revealed to have advanced pulmonary arterial hypertension (PAH) with a mean pulmonary arterial pressure (PAP) of 79 mmHg. Although both shunts had bidirectional flow, based on the results of acute pulmonary vasoreactive testing, one-stage surgical closure was performed followed by up-front combination therapy for post-operative pulmonary hypertensive crisis and residual PAH. At 14 months after the surgery, her symptoms were markedly improved, and her mean PAP had dramatically decreased to 13 mmHg.