Older adults with sepsis undergoing emergency laparotomy show varied outcomes based on BMI, affecting surgical decision-making.

• 30-day mortality in this group is 31.6%.
• Obesity class II is linked to lower 30-day mortality (adjusted odds ratio 0.55) but increases risks of ventilator dependence >48 hours (1.48) and deep vein thrombosis (2.00).
• Obesity class III is tied to significantly higher rates of pulmonary embolism (5.55) and non-home discharge (3.31).

Consider obesity classifications when evaluating surgical risks to improve patient selection and inform postoperative care strategies.