Surgical atrial septectomy using a Kerrison clamp, which is used in neurosurgery, was done in four elder infants without extra-corporeal circulation. Two (6 and 4 months old) had an atresia of left atrio-ventricular valve with small atrial septal defect, one (8 months) had a transposition of great arteries with closing multiple ventricular septal defects, and one had a pure pulmonary atresia. A purse string suture was put on the right atrial appendage and the clamp in a closing position was inserted into the left atrium through the appendage and the atrial septum. The edge of the atrial septal defect and/or patent foramen ovale was hooked by pulling it slowly. It was closed strictly and pulled out together with a resected atrial specimen. This technique is safer and easier than the Blalock-Hanlon technique and atrial septectomy under extra-corporeal circulation for elder infants for whom balloon atrial septostomy is difficult to be done.