Acute poststernotomy mediastinitis is a serious complication of cardiac surgery and is associated with high mortality. Conservative treatment with local debridement, irrigating-suction systems, and specific antibiotic therapy is sometimes inadequate. Omentoplasty is occasionally used for reconstruction and the treatment of various chest diseases. This useful procedure is most often indicated for suppurative processes and radionecrosis, to complement myoplasty, or to cover a chest wall prosthesis. When used to treat poststernotomy mediastinitis secondary to cardiac surgery, omentoplasty improves control of infection and prognosis. We describe 2 cases of poststernotomy mediastinitis secondary to cardiac revascularization surgery in which omentoplasty was an effective treatment. Excellent control of infection was achieved.