Transcatheter closure of the fossa ovalis atrial septal defect with adequate rims has become the procedure of choice in recent times. We report our experience with 439 patients who were selected for percutaneous device closure and 430 of whom underwent transcatheter closure of fossa ovalis atrial septal defects from May 1997 to May 2006. Device closure was not attempted in the remaining nine patients after initial evaluation due to high right atrial pressure following balloon occlusion (n=1 not parallel, high pulmonary vascular resistance (n=1), significant coronary artery disease (n=1), or the fact that the atrial septal defect was unsuitable for device closure (n=6). The anatomical size of the atrial septal defects ranged from 7-40 mm. Six patients underwent a combined procedure at the time of the atrial septal defect device closure (balloon pulmonary valvotomy in 4 cases, balloon pulmonary valvotomy and patent ductus arteriosus device closure in 1, and pulmonary ductus arteriosus coil closure in 1). The patients were in the age group of 2-77 years, the mean age being 20 years. Major complications occurred in seven cases. In 4 patients, there was device embolization immediately after deployment; there was left atrial appendage perforation, in one patient leading to cardiac tamponade during deployment of the device, and development of pulmonary edema in two patients. The cases in which device embolization took place underwent conventional surgery for atrial septal defect patch closure, while the patient with left atrial appendage perforation underwent emergency surgery (suturing of the left atrial appendage). Both patients with pulmonary edema were managed conservatively. The immediate success rate of device closure was 96.9%. All but one patient with multiple defects had no residual shunt at follow-up. On three months' to nine years' follow-up, the device remained stable, with no significant residual shunt and no history of thrombus formation on transthoracic echocardiography.