Surgical closure of atrial septal defect is considered a low risk procedure. Various minimally invasive surgical techniques spread over the conventional full-length sternotomy. But the risk profile and complication rates of the minimally invasive closure of atrial septal defect are not revealed sufficiently. We present the results of atrial septal defect surgery via small thoracotomies: right anterolateral, right posterolateral, partial sternotomies and full-length median sternotomies. Ninety four patients underwent surgical closure of atrial septal defect via minimal approaches through the period from February 1999 to December 2001. Via median sternotomies were operated 85 patients. Right anterolateral group consisted of 17 patients, right posterolateral - 68, partial sternotomies - 9. The intracardiac period of operation was performed on electrical fibrillation under mild hypothermia. Median bypass time was 33 min. in right anterolateral, 31 min. - right posterolateral, 32 min. - partial sternotomies, 37 min. - median sternotomies. Median fibrillation time was 21 min. in right anterolateral, 18 min. - right posterolateral, 15 min. - partial sternotomies, 21 min. - median sternotomies. There were no technical procedure related complications in minimally invasive group. Intrahospital morbidity consisted of 6 pneumonias, 4 pleural effusions. There were 3 pneumonias, 2 pleural and 2 pericardial effusions in median sternotomies group.