Coronary artery bypass graft (CABG) procedures are among the most frequently performed surgical procedures in the United States. People with cardiovascular disease who also have diabetes have a greater risk of poor outcomes after CABG procedures than patients who do not have diabetes. This literature review examines current information regarding perioperative blood glucose (BG) control. It emphasizes BG control in adults during the hypothermic period of cardiopulmonary bypass. Hyperglycemia, not the diagnosis of diabetes, significantly increases the risk of adverse clinical outcomes, longer hospitalizations, and increased health care costs.