Pulmonary artery stenosis after lung transplantation is a rare complication. It usually requires surgical correction but even after that the outcome is not favorable. The patient was a 53-years-old woman who was candidate for lung transplantation surgery due to pulmonary fibrosis. After 7 months on waiting list, with severe limitations in daily living activities, she received a single lung transplant in 2007. The surgery was performed without any complication. One day after surgery, blood oxygen saturation level did not increase and patients got dependant to oxygen supplementation through mask with reservoir bag. In bronchoscopy, black-and-white exudates and black membrane that blocked the main bronchus in the transplanted lung was observed. After bronchial lavage the membrane and exudates were successfully removed and patient received antibiotics for Aspergillus infection and Methylprednisolone pulse therapy for evidences of graft rejection. Despite success in treatments of the mentioned complications, the condition of the patient deteriorated and she became totally dependent to supplement oxygen, oxygen consumption level had increase and pulmonary artery pressure was increasing gradually. With suspicion to pulmonary artery stenosis, bronchial CT-Scan with contrast was performed 13 days after transplantation surgery which showed a 50% stenosis. Trans-esophageal echocardiography also showed a stenosis with 40 mmHg gradient. 18 days after transplantation surgery, percutaneous balloon angioplasty was performed which was initially successful but re-stenosis occurred. Seven days later, another balloon angioplasty with stent insertion was performed. After the procedure, the gradient has been removed. Patient was discharged 30 days after transplantation. Follow-up after 10 months revealed not stenosis and the stent was working properly. We conclude that pulmonary artery stenosis could happen very early after lung transplantation and percutaneous balloon dilation with stent insertion is an effective treatment.