Purpose <p>Obesity is a major risk factor in Obstructive sleep apnea (OSA), which is a prevalent disease that leads to significant morbidity. Multi-level Sleep Surgery (MLS) is a method of treatment for patients who cannot tolerate continuous positive airway pressure. Obesity has previously been identified as a risk factor that may decrease the success rate of MLS. The purpose of our study is to assess the success rates of MLS in obese patients.</p> Methods <p>A retrospective cohort study in 109 adults that underwent MLS in our institution. All the participants completed pre-operative and post-operative level 1 polysomnography. They were divided into four groups as per their body mass index (BMI): Normal (BMI &lt; 25), overweight (25–30), obese (30–35), morbid obese (&gt; 35) and the variables were compared. We measured the surgical success as defined by Sher Criteria (AHI drop &gt; 50% from preoperative baseline and AHI &lt; 20) and cure rates (AHI &lt; 5).</p> Results <p>The average BMI was 30.9 pre-op and 30.4 post-op. The mean AHI was 29.8 pre-op and decreased to 10.1 (<i>p</i> &lt; 0.001) and the Epworth Sleepiness Scale from 12.9 to 4.8 (<i>p</i> &lt; 0.001). There were 13, 31, 43, and 22 patients in normal, overweight, obese and morbidly obese groups, respectively. The surgical success rate as defined by Sher’s criteria was 84%, 84%, 72%, and 77% in the respective groups, with no statistical difference (<i>p</i> = 0.662). Moreover, the cure rate was 77%, 45%, 44%, and 45%, with no statistical difference (<i>p</i> = 0.192). The AHI reduction was 9.93, 19.73, 21.1 and 22.8 in the respective groups. A linear regression analysis revealed no significant difference in assessing the surgical success and cure rates as BMI increases.</p> Conclusion <p>Data regarding MLS success rates on obese patients is scarce. The current study demonstrates that MLS can offer positive outcomes for this population. However, further studies are warranted to investigate this relationship.</p> Level of evidence <p>3.</p>