The study consisted of all patients undergoing surgical repair of isolated secundum type atrial septal defect in patients ages 35 years or older for the period from October 1986 to October 1991. ASD was closed with direct suture in all patients. Response to surgery was excellent. Two patients who had atrial fibrillation was taken low-dose warfarin therapy to prevent stroke. All patients survived operation, and improved by at least one New York Heart Association functional classification. An old age was not a contraindication to surgery.