Background <p>Obesity is a risk factor for the development of a large hiatus hernia. Such hernias are often symptomatic and negatively impact quality of life. However, surgeons can be reluctant to operate on obese patients due to concerns of operative complexity, early hernia recurrence, and increased morbidity. To evaluate this, we assessed the perioperative risks and short-term outcomes following surgery in obese and morbidly obese patients.</p> Methods <p>Patients who underwent repair of a large hiatus hernia (≥50% intrathoracic stomach) from January 2000 to December 2023 were identified from a prospective database. Patients were categorised based on body mass index (BMI) into 3 groups: non-obese (BMI &lt; 30.0), obese (BMI 30.0–34.9), and morbidly obese (BMI ≥ 35.0). Perioperative and postoperative outcomes were compared.</p> Results <p>915 patients were included (non-obese: 519 [56.7%], obese: 276 [30.1%], morbidly obese: 120 [13.1%]). Morbidly obese patients were younger (69.2 vs 65.8 vs 64&#xa0;years, <i>p</i> &lt; 0.001) and more likely to be female (60.9 vs 79.7 vs 83.9%, <i>p</i> &lt; 0.001). There were no differences in conversion rates (0.8 vs 0.7 vs 1.7%, <i>p</i> = 0.592), operative time (106.4 vs 103.4 vs 113.6&#xa0;min, <i>p</i> = 0.074), or length of stay (2.8 vs 2.48 vs 2.57&#xa0;days, <i>p</i> = 0.063). We found no differences in major complication (4.0 vs 2.9 vs 1.7%, <i>p</i> = 0.435) or return to theatre rates (2.7 vs 1.1 vs 1.7%, <i>p</i> = 0.475). 90-day mortality rates were low for all groups (0.2 vs 0.4 vs 0%). Postoperative heartburn severity was lowest in non-obese patients (0.94 vs 1.86 vs 1.21, <i>p</i> = 0.010). There were no differences in postoperative regurgitation severity (1.02 vs 1.30 vs 1.74, <i>p</i> = 0.185) or overall satisfaction (8.74 vs 8.62 vs 8.91, <i>p</i> = 0.702).</p> Conclusion <p>Large hiatus hernia repair is safe and effective in obese and morbidly obese populations.</p> Graphical abstract <p></p>