Pulmonary artery aneurysm usually carries an ominous prognosis due to the associated pulmonary hypertension. In July 1981, a patient with a huge aneurysm of main pulmonary artery secondary to pulmonary hypertension and bacterial endocarditis due to a patent ductus arteriosus was treated by resection of the aneurysm and Dacron patch graft replacement and closure of the patent ductus arteriosus. The immediate postoperative result was excellent. We now report the surgical treatment, clinical course, and one and half years follow up of the patient.[KTCS 1982;4:381-386]