The purpose of this study was to assess cardiac remodeling and to determine factors predicting the occurrence of atrial arrhythmia after surgical closure of atrial septal defect (ASD) in adults. Retrospective study including 33 adult patients (> 20 years old, mean age: 34 ± 11 years, 26 women) who underwent surgical closure of secundum or sinus venosus ASD. Before operation, all patients had dyspnea and 15% were in NYHA III-IV. Sinus rythm was present in 85% of patients. The ratio of pulmonary to systemic blood flow was calculated, yielding a mean of 2,8 ± 1 and pulmonary artery hypertension (PAH) was observed in 80% of patients with a mean value of 41,3 ± 10 mmHg. The ASD were closed by pericardial or Dacron patch in 97% of cases. Operative death was observed in 2 cases. In survival patient, with a follow-up of 97 ± 57 months, regression of right ventricular dilatation and PAH occurred in the first post-operative month and was maintained at late follow-up. Atrial arrhythmia occurred in 5 patients and were determined by older operative age (P = 0.003) and the absence of cardiac remodeling after surgery. Surgical correction of ASD in adults is safe and efficacious. Cardiac remodeling after ASD closure in the adult is a common and an early event and prevents late morbidity which is in most cases due to arrhythmias. The mode of closure does not seem to significantly impact remodeling.