Four instances of mediastinal wound infection occurred in 100 patients who underwent bilateral internal mammary artery (IMA) mobilization for coronary bypass. Debridement of 3--5 mm of the sternal edges was performed 6--18 days after the primary operation, and 2 patients required additional, anatomically limited debridement. Wounds were allowed to heal by secondary intention. The wounds of 3 patients healed by 4, 7, and 16 months; they had patent grafts at the postoperative or 1-year catheterization; and they returned to work and are free of angina. The fourth patient died of renal and respiratory failure 3 months after the operation; his wound was healing and had not required additional debridement. These observations indicate that bilateral IMA mobilization does not result in avascularity of the sternum, which required only limited debridement and quickly formed granulation tissue from the periosteum and marrow.