The study showed that mediastinitis can be diagnosed clinically by sternotomy wound discharge and sternal rocking, and can be diagnosed laboratory by elevated leucocytic count and culture of wound discharge ,also can be diagnosed radiologically by presence of retrosternal collection in the CT. Our study showed that MRSA, and gram negative endotoxemia carries a high mortality rate.The study showed that early management of mediastinitis with omental flap carries the best prognosis in comparison to old methods of management as rewiring which usually fails due to persistence of infection.