Purpose : Transcatheter closure of atrial septal defects (ASD) is currently established therapy as an alternative to surgery. However it may troublesome to close ASD with septal aneurysm, especially multiple ASD with aneurysm. We report early and intermediate-term results after closure of ASD with septal aneurysm using the Amplatzer septal occluder (ASO). Methods : 92 patients underwent transcatheter closure of secundum ASD or patent foramen ovale using the ASO. Among them, there were 7 patients who had ASD with septal aneurysm and treated percutaneouly using ASO between Aug 2008 and Apr 2011. All patients were female, the median age was 35 years (range : 4-61 years) and their median weight was 35 kg (range : 14-52 kg). Results : The median number of multiple ASD was 3 (range: 1-4), the median septal excursion was 8 mm (range : 5-10 mm), the median diameter of largest ASD measured with transesophageal echocardiography was 17 mm (range : 12-20 mm), the median balloon stretched diameter was 20 mm (range : 13-23 mm), and the median size of device was 20 mm (range : 13-24 mm), was little difference with balloon stretched diameter. There were no significant complications after ASD closure, but there were 5 minor complications : unstable position of ASO (3), small pericardial effusion (1), residual shunt (1). Conclusion : Transcatheter closure of ASD with aneusym using ASO is effective therapy. However, minor complications such as unstable ASO or pericardial effusion can happen, so an appropriate selection of patients and device in relevance to size and anatomy of ASD is important for successful closure in patients with ASD with aneurysm.