This report documents our early experience with minimally invasive direct-access surgical repair of atrial septal defect (ASD) in adults. We have developed minimally invasive techniques for direct-access ASD repair in adults while maintaining the efficacy of the open operative procedure. Between June 1996 and September 1998, 59 consecutive patients underwent repair of ASD, 34 (58%) of whom underwent minimally invasive direct-access surgical closure of ASD through a right parasternal, submammary, or upper hemisternotomy incision. Twenty-three (68%) were secundum type ASD, 5 (15%) were sinus venosus types, 2 (6%) were primum types, and 4 (12%) were patent foramen ovales. Twenty-six (77%) were women (mean age 39 ± 15 years, range 18 to 79). The mean pulmonary-to-systemic shunt ratio (Qp/Qs) was 2.3 ± 0.6 (n = 15). There were no operative or late deaths. Follow-up was 100% complete. Four patients (12%) developed major complications. All were alive and well at the time of follow-up and there was 1 late arrhythmia (atrial fibrillation). In all but 1 patient, New York Heart Association functional class was improved or unchanged (1.47 ± 0.51 vs 1.06 ± 0.25, p = 0.0001). These results indicate that minimally invasive direct-access repair of ASD in adults is safe and effective, and is broadly applicable to the entire spectrum of defects.