Background: Obesity may complicate CC surgery, which can result in potential AC delays. We aimed to determine the effect of body mass index (BMI) and body surface area (BSA) on CC outcomes, accounting for variations in the time interval between surgery and AC. Methods: We analyzed a population-based cohort of patients from Alberta, Canada who were diagnosed with stage III CC from 2011 to 2016 and underwent AC. Patients were grouped based on their baseline BSA (underweight, < 20 kg/m²; normal, 20-24; overweight, 25-29; obese ≥ 30) and BMI (< 2 m² vs ≥ 2 m²). Logistic regression models were constructed to examine the effect of BMI/BSA on delays between surgery and AC. The Kaplan-Meier method was used to estimate overall (OS) and cancer-specific survival (CSS) and Cox proportional hazards models were developed to evaluate the impact of BMI/BSA on these outcomes, adjusting for confounders. Results: We examined 915 patients: median age was 64 years, 510 (56%) were men and 155 (17%) had a Charlson comorbidity index (CCI) ≥ 2. In this cohort, 126 (14%), 623 (68%) and 166 (18%) were stage IIIA, IIIB and IIIC, respectively. In total, 132 (14%) were underweight, 452 (49%) normal weight, 233 (26%) overweight and 98 (11%) obese. Based on the Mosteller formula, 527 (58%) patients had normal BSA and 368 (42%) had high BSA. Obese patients were more likely to be men (67% vs 56%, p < 0.001) and had worse CCI (28% vs 17% with CCI ≥ 2, p = 0.03) when compared to non-obese patients. Neither BMI (p = 0.14) nor BSA (p = 0.44) correlated with AC delays after surgery. Similar OS and CSS were observed regardless of BMI and BSA (p = 0.76 and 0.80 for OS and p = 0.60 and 0.89 for CSS, respectively). In multivariate Cox models, only worse nodal stage was associated with inferior OS and CSS (HR 4.74, 95%CI 1.96-11.47, p < 0.001 for OS; HR 4.92, 95%CI 1.42-17.00, p = 0.006 for CSS, comparing IIIC vs IIIA), but BMI and BSA were not (see Table). Conclusions: Obesity as measured by BMI and BSA did not correlate with AC delays or worse outcomes in stage III CC patients.