A 6-year-old boy underwent one stage operation for atrial septal defect (ASD) and funnel chest. The procedure began with removal of cost-sterno complex (plastron) following median skin incision. Plastron was kept in cold saline with antibiotics during ASD closure, and sterno-costal elevation method was performed. Simultaneous operation for heart disease and funnel chest is profitable in preventing postoperative circulatory or respiratory complications, in avoiding problems of two stage operation such as adhesion and mental stress of the patients. In addition, wide exposure and easy approach to the heart is available with this one stage procedure. Although current refinement both of cardiac and thoracic surgery has encouraged the possibility of simultaneous corrections for heart disease and funnel chest, much precautions against bleeding and infection are necessary for the satisfactory surgical result.