Background: Secundum Atrial Septal Defects (ASDs) are the most common type of atrial septal defects. Today, using different types of occluders, transcatheter closure is widely used to treat ASD and has replaced the surgical procedure in anatomically suitable patients. This study was performed to evaluate the short-term clinical outcomes of treatment of adult patients requiring an ASD device closure referred to Shahid Chamran Cardiovascular Center in Isfahan, Iran.Methods: All patients who underwent ASD treatment using transcatheter closure at Shahid Chamran Cardiovascular Center in 2020 and 2021 were recruited in this retrospective descriptive study. The characteristics of the treated lesion and the cardiovascular complications during treatment were recorded immediately and one month after treatment, and their frequency was reported as a percentage.Results: A total of 70 patients (47 females and 23 males) with a mean age of (39.81±12.56) were investigated in this study. The number of difficult anomalies was 46 (65.7%), and the most common type was the deficient aortic rim. In terms of the incidence of vascular complications observed, hematoma, bleeding, and pseudoaneurysm were observed in 8 patients. The most common cardiac complication was atrial fibrillation, which occurred in 12 patients. No cardiovascular complication was observed during the one-month follow-up.Conclusion: The results of this single-institute study showed that ASD treatment by the transcatheter procedure using an ASO device at Shahid Chamran Cardiovascular Center was performed safely and successfully with very few complications. The short-term analysis of the outcomes indicated no major complication, death, and device malposition.