['Use of both internal thoracic arteries has been limited in diabetic patients fearing an increased incidence of deep sternal wound infection. We analyzed this concern by querying The Society of Thoracic Surgeons Database.', 'Diabetic patients who had isolated coronary artery bypass graft surgery during 2002 to 2004 were included if they had no prior bypass surgery, two or more distal bypasses, and a left internal thoracic artery bypass. Group B (both internal thoracic arteries) was compared with group L (left internal thoracic artery only).', 'The incidence of deep sternal wound infection for all patients undergoing isolated first-time bypass surgery was less than 1%. Of these, 120,793 patients met criteria for inclusion: group B, 1.4% (1732); and group L, 98.6% (119,061). Group B had a higher crude (unadjusted) deep sternal wound infection rate of 2.8% (49) versus 1.7% (1969; p = 0.0005) in group L, with an estimated odds ratio of 2.23 (95% confidence interval, 1.69 to 2.96). Group B had a similar crude mortality rate of 1.7% (30) versus 2.3% (2785; p = NS) in group L, with an estimated odds ratio of 1.110 (95% CI, 0.78 to 1.59; p = NS). Patients in group B were younger, mostly male, had a lower serum creatinine level, and were more often current smokers; less commonly, they were insulin dependent, diagnosed with pulmonary or vascular disease, or on dialysis. Other risk factors for deep sternal would infection included female gender, insulin dependence, peripheral vascular disease, recent infarction, body mass index exceeding 35 kg/m2, and use of blood products.'] Does use of both internal thoracic arteries in diabetic patients increase deep sternal wound infection?