Background Inguinal hernias account for nearly 800,000 surgical repairs annually. While generally associated with good outcomes, elective inguinal hernia repair (IHR) has postoperative complications in over 10% of cases. Identifying modifiable risk factors remains important. As an important risk factor, obesity has previously been shown to have a negative impact on surgical outcomes. However, limited research has analyzed the effects of obesity specifically on robot-assisted IHRs. This study aims to determine whether Body Mass Index (BMI) is associated with a combined outcome of postoperative complications within 30 days of robotic IHR. Methods This retrospective cohort study analyzed 290 patients who underwent robotic IHR at a single center. BMI was primary independent variable, and the outcome was any complication within 30 days of surgery, comprising wound-related complications (surgical site infection, hematoma, or seroma) and other adverse events (urinary retention, severe pain, reoperation). Univariate analysis was used to evaluate associations between covariates and the primary outcome. A multivariable logistic regression model was constructed with the statistically significant covariates in the univariate analysis. Results Of the 290 patients analyzed, 23 (7.9%) experienced a postoperative complication within 30 days according to the criteria. Based on the multivariate logistic regression, higher BMI was independently associated with increased odds of complication (OR 1.10, 95% CI 1.01-1.20, p = 0.0214). Use of anticoagulants (OR 7.15, 95% CI 1.30-32.70, p = 0.0135) and ASA class ≥3 (OR 2.68, 95% CI 1.02-6.76, p = 0.0386) were also significantly associated with postoperative complication. The model demonstrated acceptable discrimination (AUC 0.723) and good fit (Hosmer-Lemeshow p = 0.47). Additional univariate analyses were performed for surgical site occurrences (SSOs) and emergency department (ED) visits. For SSOs, ASA class ≥3 was significantly associated with increased odds (OR 7.60, 95% CI 1.81-38.0, p = 0.0066). For ED visits, male sex was associated with decreased odds compared to female sex (OR 0.21, 95% CI 0.05-1.12, p = 0.048), and concomitant procedures were associated with increased odds (OR 5.53, 95% CI 1.19-28.8, p = 0.028). Conclusion Higher BMI, ASA Class (≤2 vs. ≥3), and use of anticoagulants were each independently associated with an increased odds for postoperative complication within 30 days of robotic IHR. This suggests that patient-specific risk factors should be considered during perioperative planning, and selected patients may benefit from preoperative weight-loss prehabilitation programs. Future work should focus on refining risk stratification and assessing potential interventions for at risk populations.