To determine the incidence, the mortality, the risk factors and the most appropriate method for treatment of sternal infections, 9,742 charts were reviewed retrospectively of patients having undergone a sternotomy for cardiac surgery at the Montreal Heart Institute. One hundred and eleven sternal infections (1.1%) were identified: 55 (0.57%) superficial, 56 (0.57%) profound (mediastinitis). The treatment for these profound infections was either debridement, open or closed with drainage irrigation, pectoral flap closure-repair, or epiplooplasty closure. The risk factors for those patients experiencing profound infections were diabetes, obesity, length of the surgical intervention, the time spent in the operating room, and the duration of endotracheal intubation. Eleven of the 111 patients died. The average length of hospitalization were similar for those patients treated by pectoral flap repair and by the epiplooplasty closure. All patients (100%) treated by the epiplooplasty closure developed an epigastric hernia. Six cases of recurrent infection were observed in the group treated by debridement. The average hospital stay was shortened for those patients benefiting from the pectoral flap and epiplooplasty closures. A high incidence of mortality is associated with profound sternal infection. The methods of treatment are various. We recommend as treatment of choice, the pectoral flap closure because there is relatively low risks with this procedure, little to no recurrence of infection, a shorter hospital stay and this procedure does not provoke epigastric hernia.