In this report a case of 46 years old female patient with diagnosis of Precoarctation Aneurysm (PCA) is presented. She was earlier operated for a hydatid cyst of lung with left thoracotomy. After thoracotomy, as the mass was pulsatile, chest had been closed for further studies. Results of CT scan and angiography revealed the presence of aneurysm precoarctation in the distal arch of aorta. Surgery with mid sternotomy and trap door in left intercostal space with the aid of Cardio Pulmonary By pass (CPB) was performed. In surgery field there was precoarctation aneurysm with a small Patent Ducts Arteriosus (PDA) and also aortic coarctation existed. Aneurysmectomy, closure of PDA and repair of coarctation was done interpositionally with dacron graft No 27 mm. Patient was discharged from hospital a week later in a good condition.