Purpose ‘Failure to rescue’ (FTR) has been recognised as a critical factor influencing patient outcomes in colorectal surgery, particularly following major complications such as anastomotic leak (AL). This retrospective study aimed to evaluate the rate and impact of FTR following AL in patients undergoing colorectal cancer resection, and identify independent predictors of FTR-AL. Methods The Bowel Cancer Outcomes Registry was used to identify all patients undergoing colorectal resection with primary anastomosis from 2007-2024. The primary outcome of interest was FTR- AL, defined as in-hospital or 30-day mortality following AL. Univariate and multivariate logistic regression models were used to identify independent predictors of FTR-AL. Results Overall, 31,610 patients were included, with AL occurring in 1,569 (5.0%). AL was associated with higher rates of almost all other medical and surgical complications. Associations between AL and its sequelae included return to theatre (OR 45.1, 95% CI 39.9-51.0), enterocutaneous fistula (OR 35.4, 95% CI 17.7-74.4), and sepsis (OR 30.9, 95% CI 25.4-37.7). In-hospital or 30-day mortality was 1.4%. The rate of FTR-AL was 5.9%, and 21.4% of all deaths occurred following AL. FTR-AL was independently predicted by older age (adjusted OR 1.08, 95% CI 1.04-1.12, p<0.001), ASA score of 4-5 (adjusted OR 6.75, 95% CI 2.27-20.14, p<0.001), and sepsis (adjusted OR 3.32, 95% CI 1.65-6.65, p<0.001). Conclusion AL contributes to over one in five deaths following colorectal cancer surgery. Elderly and comorbid patients, and those who develop sepsis, are at higher risk of FTR-AL. Further efforts should be directed towards early detection of AL.