Background: We evaluated the outcomes of totally endoscopic minimally invasive surgery for atrial septal defect (ASD) using a glutaraldehyde-treated autologous pericardial patch in the transcatheter interventional era. Methods and Results: We retrospectively reviewed 37 consecutive patients who underwent totally endoscopic ASD closure with a glutaraldehyde-treated autologous pericardial patch between June 2011 and April 2015. All patients had been deferred from catheter-based intervention for clinical or anatomical reasons. We analyzed operative outcomes and postoperative echocardiographic data. The mean age was 45.7 16.5 years, and 25 patients (67.6%) were women. The mean ratio of pulmonary to systemic flow was 2.4 0.7. Six patients (16.2%) underwent concomitant tricuspid valve repair, and 3 patients (8.1%) underwent concomitant atrial fibrillation surgery. There were no operative deaths, and the median length of hospital stay was 5 days. Postoperative echocardiography revealed trivial residual shunt in 1 patient. During the follow-up period, there were no re-interventions for ASD or readmission for heart failure. Follow-up echocardiography revealed no recurrent shunt or calcification of the autologous pericardial patch. Conclusions: Totally endoscopic ASD closure with a glutaraldehyde-treated autologous pericardial patch demonstrated excellent outcomes. It is a useful option for patients with unfavorable anatomy or other reasons excluding transcatheter intervention.