Anomalies of pulmonary veins are uncommon and vary widely in their anatomic spectrum and clinical presentation. A 20-year-old woman with complaints of effort-induced dyspnea and easy fatigability was diagnosed with a third left pulmonary vein with abnormal return and arteriovenous fistula accompanied by a secundum atrial septal defect (ASD). Complete surgical repair was performed by ASD closure with a pericardial patch and triple ligation of the left vertical vein and associated third pulmonary vein. The patient was discharged on the seventh postoperative day in good health. Her last control examination was performed in the second postoperative year, revealing normal echocardiographic findings with an excellent clinical course.