Background: End-stage renal disease (ESRD) and renal replacement therapy (RRT) are important risk factors for post-operative morbidity and mortality but remains poorly reported in colorectal surgery. This study aims to evaluate postoperative outcomes of ESRD patients under RRT undergoing colorectal resection. Methods: All ESRD patients under RRT who underwent colorectal resection between 2006 and 2019 were retrospectively reviewed. Perioperative outcomes were analysed, such as risk factors of postoperative complications. Results: Forty-two patients were analysed, including 27 emergency and 15 elective surgeries. The most frequent indication was acute colonic ischemia for emergency and malignancy for elective procedures. Laparoscopic approach was used in 12 patients (29%), without difference between elective and emergency groups. Postoperative severe complications rate (including deaths) was 50% (21/42), including 56% (15/27) and 40% (6/15) in emergency and elective groups, respectively (p ¼ .334). Anastomotic leak was observed in 3 of the 23 patients (13%) undergoing digestive anastomosis, (1 in emergency and 2 in elective groups, p ¼ .246). The postoperative mortality rate was 29%, not significantly different between groups. The median hospital stay was 14.5 days (8-42). At univariate analysis, history of cardiac event (p ¼ .028) and open approach (p ¼ .040) were associated with severe complications, and ASA score >3 (p ¼ .043), history of cardiac event (p ¼ .001) and diabetes (p ¼ .030) associated with mortality. Conclusions: Colorectal surgery in ESRD patient exposes to high risk of morbidity and mortality, even in the elective setting, especially in patients with comorbidities like cardiac event and diabetes. Careful patient selection and closed management is required in such fragile patients.