Transcatheter closure of atrial septal defect (ASD) has become a well-established surgical intervention for patients with atrial fibrillation (AF). The incidence of AF is still increased after ASD closure, compared with an age-matched general population. However, radiofrequency catheter ablation which has become an increasingly common therapy for AF is underutilized due to the difficulty of obtaining transseptal access in the presence of the closure device. We describe an extremely challenging case in which the transseptal puncture (TSP) was successfully completed with the use of a peripheral balloon dilatation catheter in the atrial septal defect (ASD) patient with an atrial septal occluder. For patients with fibrotic and thickened devices, peripheral balloon dilatation can facilitate transseptal passage safely and effectively.