Purpose Aortic calcification assessed on staging CT may aid as a prognostic biomarker for postoperative outcomes in rectal cancer, potentially reflecting vascular health impacts on complications and survival in this cohort. This study investigates its associations with post-operative complications, outcomes and overall survival (OS) in a rectal cancer cohort. Methodology Analysis of 100 rectal cancer patients was taken from the ACCORD (Australian Comprehensive Cancer Outcomes and Research Database) database from 2013-2022. Aortic calcification measurements calculated using 3D SlicerTM version 5.10 with aortic calcification quantified as total calcium score (L1 to iliacs). Complications were evaluated binarily in surgical cases (n=71) using the Clavien Dindo Classification. OS was assessed from diagnosis to death or last follow-up (n=99, median 973 days). Analyses included t-tests, logistic regression for complications, and Cox regression for OS, adjusted for age and gender. Results Analysis of 100 rectal cancer patients was conducted. The mean was age 67.9 years (Range 28.7 to 95). 71 patients underwent operative management with 29 receiving palliative treatment. 14% (10/71) of cases had a Clavien Dindo complication 3 or above, with no significant correlation with increased calcification (mean score: 3632 vs. 2947 in complication vs. no-complication groups; p=0.664). Higher calcification independently predicted early cancer related mortality (HR=1.052 per 1000-unit increase, 95% CI: 1.010–1.096, p=0.014). Conclusion Aortic calcification emerges as a prognostic imaging biomarker for worse postoperative survival in rectal cancer, independent of complications. Further data from this data set will need to be added to support its integration into risk stratification models.