Objective To evaluate atrial septal defect (ASD) occlusion employing a small right anterior thoracotomy approach. Methods A total of 21 patients with ASD underwent general anesthesia and 2 -3 cm incision was made in the fourth right intercostal space. Utilizing transesophageal or transthoracic echocardiography, the occluder was released using a monotube unit. Results All patients were occluded successfully. No patient required open surgery utilizing extracorporeal circulation. There were no major complications and no evidence of residual atrial shunt. Conclusion ASD occlusion via a minimal surgical incision is safe, less invasive, and has excellent outcomes.