Cardiac surgery, while lifesaving, is often accompanied by pulmonary complications that can significantly affect patient outcomes. Common complications include atelectasis, pleural effusion, acute respiratory distress syndrome (ARDS), pneumonia, phrenic nerve injury, diaphragmatic dysfunction, and pneumothorax, all of which can lead to prolonged hospital stays. Certain risk factors heighten the likelihood of these conditions. This chapter explores these complications in detail, highlighting the role of effective interventions such as physiotherapy, noninvasive ventilation, perioperative prophylaxis, and early ambulation in prevention. Emphasizing preventive measures, early detection, and advanced management strategies is crucial for improving outcomes in cardiac surgery patients.