['Patient and technical factors influencing the postoperative infectious complications (ICs) after elective colorectal resections are satisfactorily described. However, the underlying disease-related factors have not been extensively evaluated. This study aimed to measure the effect of malignancy on postoperative surgical site and extra surgical site infections after elective colorectal resection.', 'This study is a bicentric retrospective matched pair study of prospectively gathered data. Between 2004 and 2013, 1104 consecutive patients underwent colorectal resection in two centers. Patients undergoing elective resection with supraperitoneal anastomosis for benign diseases (excluding inflammatory bowel disease) (group B, n\u2009=\u2009305) were matched to randomly selected patients with malignancy (group M, n\u2009=\u2009305). The matching variables were age, gender, American Society of Anesthesiologists (ASA) score, malnutrition, type of resection, and surgical approach. We compared the 30-day IC rates between patients with benign diseases (group B) and malignancy (group M). Multivariate logistic regression analysis was performed to identify the risk factors for ICs.', 'Group M had a higher overall rate of IC (25.6 vs 16.1 %, P\u2009=\u20090.004) as well as a higher risk of extra surgical site infections (P\u2009=\u20090.007) and anastomotic leakage (P\u2009=\u20090.039). The independent risk factors for ICs were malignancy (odds ratio (OR)\u2009=\u20092.02; P\u2009=\u20090.002), age ≥70 years (OR\u2009=\u20091.73, P\u2009=\u20090.018), tobacco history (OR\u2009=\u20091.87; P\u2009=\u20090.030), and obesity (OR\u2009=\u20091.68; P\u2009=\u20090.039).'] Is malignancy a risk factor for postoperative infectious complications after elective colorectal resection?