BACKGROUND: For many colorectal cancer patients, primary surgery is the standard care of treatment. Further insights in perioperative care are crucial. The aim of this study is to assess the prognostic value of body composition for postoperative complications after laparoscopic and open colorectal surgery. METHODS: From January 2013 to 2018 all consecutive patients who underwent surgery for colorectal cancer were enrolled in this study. Patients with a preoperative CT-scan <
90 days before surgery were included. All CT-scans were obtained retrospectively, and body composition was analysed using a single transverse slice at the level of the third lumbar vertebra (L3) within the Slice-O-Matic-software. The studied outcome measure was the occurrence of major postoperative complications (Clavien-Dindo grade ≥3b). RESULTS: A total of 1213 patients were included in the final analyses. Multivariable analyses showed that patients with low-skeletal muscle mass Z-score (OR 0.67, 95 % CI 0.45-0.97, p = 0.036) or a high visceral adipose tissue Z-score (OR 1.56, 95 % CI 1.06-2.29, p = 0.023) were significantly associated with an increased risk of developing major postoperative complications after open surgery. In the laparoscopic group, all six body composition parameters were not significantly associated with an increased risk of developing a major postoperative complication. CONCLUSIONS: In this study, open colorectal surgery in patients with either low skeletal muscle mass or high visceral adipose tissue mass was associated with increased risk of postoperative complications. Laparoscopic surgery did not show this correlation. This demonstrates the importance of using minimal invasive surgery in colorectal cancer patients and implementing this as standard care.