Introduction. Surgical site infection (SSI) is a well-known complication of colorectal surgery associated with increased morbidity and hospital stay. Antimicrobial prophylaxis can reduce the risk of SSI by as much as 75%. Extended-spectrum β-lactamase (ESBL)-producing pathogens make the successful use of such prophylaxis a challenge and are a real threat to patient care following colorectal surgery. Objective. The aim of this study is to report the common characteristics of SSIs after colorectal surgery and to highlight the prevalence, risk factors, and clinical relevance of ESBL infections among these patients in a tertiary center. Materials and Methods. All patients who underwent bowel resection operation (ie, laparoscopy, laparotomy, or laparoscopic-assisted colectomy) for benign or malignant colorectal disease were identified retrospectively from the prospective database of the colorectal department in the authors’ tertiary center from March 2015 to March 2016. Results. There were 123 patients included in this study, of which 21% (n = 26) had a SSI. The microorganisms isolated in the surgical sites included Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, methicillin-resistant Staphylococcus aureus, Proteus mirabilis, Morganella morganii, and Enterobacter cloacae. Thirty-eight percent of the wound infections grew ESBL-producing pathogens in their wound cultures and 62% grew non-ESBL microbes. Conclusions. More than one-third of the wound infections were due to ESBL-producing pathogens, which were resistant to the antibiotic prophylaxis given. Inappropriate antibiotic usage can delay postoperative recovery. High-risk patients for ESBL colonization may benefit from preoperative screening based on an established protocol. The cost effectiveness of an ESBL screening program needs to be further studied.