Hemitruncus is an uncommon congenital defect in which a pulmonary artery (PA) branch originates abnormally from the ascending aorta. Left hemitruncus is less common than a right hemitruncus. In this report, we present an isolated left hemitruncus in a neonate who showed progressive respiratory distress in the second week following delivery. At 21 days of age, the patient underwent total surgical correction of the defect, during which a direct end-to-side anastomosis to main PA without conduit interposition was employed. After a prolonged intubation period with pneumonia, the patient was discharged from hospital on the 17th postoperative day.