Diaphragmatic hernia is a very rare occurrence after cardiac surgery without complications. We report a case of a 66-year-old male who underwent double aortocoronary bypass surgery, mitral and tricuspidal annuloplasty developed bowel obstruction 5 months after the operation. X-ray demonstrated small bowel loops in the left side of the chest. A laparoscopy was performed, but during the reduction of the hernia, patient suffered bradycardia because of adhesions between bowel and pericardical sac. Operation was interrupted and patient was transferred to our hospital where a cardiac surgery unit is present. No hemodynamic or respiratory deterioration was observed. Thoracic abdominal entero-CT, transthoracical echocardiography were performed. Patient underwent second surgery in cooperation with the cardial surgical team. Sternotomy was carried out. Hernial content was drawn onto the abdomen, diaphragmatic defect was closed with a direct suture. Mini-laparotomy was performed to exclude that the herniated small bowel did not have ischaemic suffering. No morbidity was observed in the post-operative course. This case illustrates the importance of an accurate pre-operative diagnosis in order to obtain information on relationship between loops of bowel and mediastinal organs. If sternotomy is required, surgical team must be supported by a cardiac surgical team.