We prospectively compared closure and complication rates in 91 children with secundum atrial septal defects: 44 (mean age, 8.1 +/- 4.7 years) were treated surgically and 47 (mean age, 10.1 +/- 4.9 years) were treated by percutaneous Amplatzer septal occluder Complications were classified as mild, moderate, or severe. The closure rate was similar in the 2 groups: 42/44 children (95.5%) in the surgical group versus 46/47 patients in the device group (97.5%). Mild complications were observed in 17/44 patients in the surgical group vs 2/47 in the device group; moderate, 11/44 in the surgical vs 1/47 in the device group; and severe, 2/44 in the surgical group vs none in the device group. Blood products were administered to 18 patients in the surgical group and to 1 patient in the device group (P < 0.001). Transcatheter closure of secundum atrial septal defects with the Amplatzer device has the advantage of fewer complications, shorter hospitalization, and reduced need of blood products. Nonetheless, the surgeon's ability to close any atrial septal defect regardless of its size or location remains an important advantage of surgery.