Background: Surgical site infections (SSI) are a common complication of open colorectal surgery with incidence up to 20%. SSIs contribute to increased morbidity, mortality and prolonged hospital stay. Warm Humidified Carbon Dioxide Insufflation (WHCI), commonly used in laparoscopic surgery, is thought to reduce SSIs and other postoperative complications by maintaining normothermia and minimising peritoneal damage. Methods: A systematic review and meta-analysis was conducted following PRISMA guidelines. Databases searched included PubMed, OVID Medline, Cochrane Central Register of Controlled Trials, CINAHL, and OVID Embase up to September 2023. Only randomized controlled trials (RCTs) evaluating WHCI in open abdominal surgery were included. The primary outcome was SSI and secondary outcomes were core temperature, length of stay (LOS) and anastomotic leak. Meta-analysis was performed and data visualised with forest plots. Results: Six RCTs were included in the meta-analysis. The use of WHCI showed a non-significant trend towards reducing SSI rates (OR = 0.38, 95% CI [0.11, 1.30], p=0.12) and a tendency towards warmer core body temperatures at the end of surgery (SMD = 1.13, 95% CI [-0.07, 2.33], p=0.06). No statistically significant differences were observed in length of stay (LOS) between the WHCI and control groups. Conclusion: While WHCI shows potential benefits in open abdominal surgery, including a trend towards reduced SSIs and maintenance of core temperature, these findings were not statistically significant. WHCI devices were overall found to be safe. Further large-scale clinical trials are required to establish the efficacy of WHCI on postoperative outcomes in open abdominal surgery particularly in emergency surgery.