Purpose To analyze short-term outcomes of curative-intent cancer surgery in all adult patients diagnosed with colorectal cancer undergoing surgery from January 2010 to December 2019 and determine risk factors for postoperative complications and mortality. Methods Retrospective study conducted at a single tertiary university institution. Patients were stratified by age into two groups: < 75 years and ≥ 75 years. Primary outcome was the influence of age on 30-day complications and mortality. Inde- pendent risk factors for postoperative adverse events or mortality were analyzed, and two novel nomograms were constructed. Results Of the 1486 patients included, 580 were older (≥ 75 years). Older subjects presented more comorbidities and tumors were located mainly in right colon (45.7%). After matching, no between-group differences in surgical postoperative com- plications were observed. The 30-day mortality rate was 5.3% for the older and 0.8% for the non-older group (p < 0.001). In multivariable analysis, the independent risk factors for postoperative complications were peripheral vascular disease, chronic pulmonary disease, severe liver disease, postoperative transfusion, and surgical approach. Independent risk factors for 30-day mortality were age ≥ 80 years, cerebrovascular disease, severe liver disease, and postoperative transfusion. The model was internally and externally validated, showing high accuracy. Conclusion Patientsaged≥75yearshadsimilarpostoperativecomplicationsbuthigher30-daymortalitythantheiryounger counterparts. Patients with peripheral vascular disease, chronic pulmonary disease, or severe liver disease should be informed of higher postoperative complications. But patients aged ≥ 80 suffering cerebrovascular disease, severe liver disease, or need- ing postoperative transfusion should be warned of significantly increased risk of postoperative mortality.