Among all postoperative complications that appear in the first 48 hours after surgical interventions, the most common are the respiratory complications. Our retrospective study follows the clinical data of 1224 patients undergoing open heart surgery, operated between 2004-2005 at the Institute of Cardiovascular Disease and Transplantation from Târgu-Mureş. The autors followed the distribution of age, diagnosis, associated diseases, the type of surgical interventions, medical therapy in relation with the type and frequency of postoperative respiratory complications. In the above-mentioned period 218 patients had some kind of respiratory complication after open heart surgery, in 88 cases atelectasis, at 61 patients pleural collection was detected, in 17 cases pneumothorax, and others. Respiratory complications make recovery more difficult, extend the number of days passed at the intensive care unit, so prevention of these complications are as important as the specific and adequate therapy.