Iatrogenic flail chest following resection of part of the chest wall in postoperative patients is a challenging scenario for the anaesthetist. It can lead to long term disability and even death, if emergency management is not instituted. We present a case report of postoperative flail chest, following resection of upper 2/3rd of the sternum along with costal cartilages for a thymic neoplasm invasing the sternum. A 44 year old male patient, diagnosed with ‘malignant thymoma with invasion of manubrium sterni’ was posted for ‘Enbloc resection of upper 2/3 rd of Sternum and costal cartilages with Thymic tumour and chest wall reconstruction’.