OBJECTIVE Increased risk of deep sternal infections has prohibited routine bilateral internal thoracic artery grafting in diabetic patients. The technique for harvesting the skeletonized internal thoracic artery provides the potential to minimize this risk. The purpose of this study was to compare the outcome of bypass grafting with bilateral skeletonized internal thoracic arteries in diabetic and nondiabetic patients. METHODS From May 1996 to April 1998, 231 consecutive diabetic and 534 nondiabetic patients underwent bilateral skeletonized internal thoracic artery grafting. Mean age was 66 years. Compared with the nondiabetic group, the diabetic group comprised more women (29% vs 18%, P =.001), had a greater prevalence of hypertension (53% vs 44%, P =.019) and congestive heart failure (20% vs 14%, P =.016), but a lower prevalence of preoperative acute myocardial infarction (26% vs 34%, P =.027). RESULTS Operative mortality of diabetic patients was comparable with that of nondiabetic patients (3% vs 2.6%). The two groups also had similar occurrences of deep sternal infection (2.6% vs 1.7%, respectively, P =.40). Deep sternal infection was significantly more prevalent in obese, diabetic women (3/20 = 15%) than in diabetic patients without this combination of risk factors (3/211 = 1.4%, P <.0001) (odds ratio 11.1, confidence interval 2.1-59.4). Diabetic patients also had a higher incidence of stroke (3.5% vs 0.9%, P =.014). Three-year actuarial survival of diabetic patients was lower (91.3% vs 94.7%, P =.083). CONCLUSIONS Bilateral skeletonized internal thoracic artery grafting is a good surgical revascularization option in diabetic patients. Operative mortality and prevalence of sternal infection are comparable with those of nondiabetic patients. However, the risk of sternal infection in obese diabetic women is high, and for them we advocate the use of a single artery instead of bilateral internal thoracic arteries.