We report here 2 cases of deep-seated mediastinitis combined with sternal osteomyelitis after tracheal reconstruction which were successfully treated with sternectomy, in-situ or free omental transfer, and pectoralis major myocutaneous flap. In case I, an 8 year-old boy with deep seated mediastinitis and sternal osteomyelitis that developed after anterior tracheoplasty through a standard midline sternotomy. In case II, a 50 year-old female patient with mediastinal abcess and sternal osteomyelitis that developed after resection and end-to-end anastomosis of the trachea through an upper midline sternotomy. Treatments consisted of drainage and irrigation followed by wide resection of the infected sternum, placement of the viable omentum into the anterior mediastinal space, and chest wall reconstruction with a pectoralis major myocutaneous flap. The omentum was transferred as an in-situ pedicled graft in case I and a free graft in case II. Both patients have recovered smoothly wit out any events and have been doing well postoperatively.