The purpose of this study was to use the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to evaluate the incidence of postoperative surgical site infections (SSIs) between laparoscopic (LAP) and open colorectal surgery. The 2008 ACS-NSQIP Participant Use File was queried by Current Procedural Terminology codes for colorectal surgery cases. SSI rates were compared between groups using Pearson chi-square and Fisher exact tests. Univariate and multivariate analyses were performed to identify factors associated with the LAP approach and/or SSIs. A total of 7,755 LAP and 16,184 open cases were identified. The laparoscopic group had an SSI rate of 9.4 versus 15.7 per cent for the open group (P < 0.0001). There was no statistical difference in the type of SSI (superficial, deep, and/or organ space) between the two groups. Although multivariate analysis identified several factors associated with SSIs of different types, LAP was the only factor found to decrease risk, whereas wound class and operative time were found to increase risk among all categories of SSIs. Despite a significantly lower incidence of postoperative SSI, only 32 per cent of colorectal surgery was performed laparoscopically in NSQIP hospitals in 2008. Wider adoption of LAP approaches for colorectal surgery should continue to reduce SSIs.