The aim of this study is to compare the frequency of wound infection between bilateral and single internal thoracic artery (ITA) harvesting in coronary artery bypass grafting (CABG) cases. Two hundreds and thirty-four consecutive CABG cases performed harvesting either bilateral ITA (BITA) or single ITA (SITA) from January 2004 to December 2008, with or without concomitant surgery were studied. Harmonic Scalpel was used for the harvesting with skeletonization technique. The cases were divided into 2 groups: BITA group (n = 180) and SITA group (n = 54). The frequencies of wound infection were 3.7% in SITA group and 6.1% in BITA group. As to deep sternal infection, they were 1.9% in SITA group and 1.1% in BITA group. There was no significant difference between the 2 groups. Multivariate analysis of all patients showed that emergency cases, hypertension, congestive heart failure, and reopening for bleeding were identified as independent risk factors for wound infection. There were 113 diabetes mellitus (DM) patients out of all patients ; SITA group (n = 22) and BITA group (n = 91). Their wound infection rates were 4.5% and 6.6%, and those of deep sternal infection were 0% and 2.2%, respectively. There was no significant difference between them. In conclusion, BITA harvesting with skeletonized technique may be used as safely as SITA harvesting even in DM patients.