With conflicting evidence in the literature, we hypothesised that the long-term subjective outcomes of the retropubic midurethral sling (MUS) are the same in the severely obese and non-obese populations. A retrospective matched cohort study was performed on women with a BMI ≥ 35 and < 30 who had a retropubic MUS placed between 2010 and 2015 using telephone questionnaires. The primary outcome was the success rate of surgery defined by the Urogenital Distress Inventory Short Form (UDI-6) stress subscale. Statistical analysis was performed to test for associations between primary and secondary outcomes across the two groups. Seventy-eight severely obese (SOG) and 74 non-obese (NOG) were recruited. At a median time from surgery of 3.8years the success rate was 47.4% in the SOG compared to 64.9% in the NOG (p= 0.03). There was a 22% reduction in the odds of success with every 5 unit increase in BMI (p= 0.03). There were higher rates of mixed urinary incontinence preoperatively (60.3% vs. 37.8%, p= 0.006) and persistent urinary urge incontinence postoperatively (48.7% vs. 32.4% p= 0.04) in the severely obese. Lower PGI-I scores were obtained in the severely obese group indicating less improvement in symptoms from surgery. There was no difference in complication rates between the groups. Long-term subjective outcomes from the retropubic MUS are lower in severely obese women than in non-obese women with no difference in complication rates. High satisfaction and recommendation rates were found in both groups.