Tube thoracostomy is a routine intervention which is used in cardiovascular surgery clinics. Although it is a life-saving intervention in most cases, it has serious complications leading to mortality. We encountered an ascending aortic perforation, an unusual complication following apical chest tube insertion, in a 71-year-old male patient who underwent coronary artery bypass graft (CABG) surgery in our clinic. This complication was managed successfully and the patient was discharged with a complete recovery. This rare but fatal complication should be considered for the patients undergoing tube thoracostomy, particularly with a toracar. It should also be noticed whether the patients have mediastinal shift in postoperative period.