Swiss cheese atrial septal defect (ASD) is a structural finding of the heart used to characterize multiple or fenestrated interatrial defects found in approximately 10% of patients with ASD. ¹ Presence of an aneurysm in the atrial septum is an additional malformation associated with fenestrated ASD that further increases the risk of arrhythmia and thromboembolic events. ^1-2 Detailed anatomy of the interatrial septum through 2D and 3D imaging serves as diagnostic and therapeutic guidance. ³ We describe a case of Swiss Cheese ASD complicated with an atrial septal aneurysm successfully repaired with a Cribriform Amplatzer Septal Occluder (ASO) via percutaneous transcatheter approach.