Background <p>Banded one anastomosis gastric bypass (BOAGB) is an efficacious surgical option for patients with obesity. OAGB has a high percentage excess weight loss reported in the literature, and the addition of a silastic ring (SR) otherwise known as a band,&#xa0;helps to reduce recurrent weight gain.</p> Methods <p>156 patients from a single centre between 2005–2008 underwent a BOAGB. A questionnaire, blood test results and electronic records were utilised at 15&#xa0;years post-operatively to identify patient outcomes.</p> Results <p>At 15&#xa0;years, the average percentage excess weight loss (%EWL) was 82.0%, the average percentage total weight loss (%TWL) was 35.9%, and the average body mass index (BMI) had reduced from 46.3&#xa0;kg/m² to 29.7&#xa0;kg/m². 106/114 (93.0%) of patients had adequate weight loss at 15&#xa0;years. 27/114 (23.7%) of patients had recurrent weight gain at 15&#xa0;years. Antihypertensives, lipid lowering therapy and hypoglycaemic medications had all reduced, and proton pump inhibitor medications had increased. There were 11 (7.1%) deaths by 15&#xa0;years, and none were directly related to the initial operation. Silastic rings were removed in 12 patients (7.7%). 21 (13.5%) patients had a conversion to a Roux-en-Y gastric bypass over 15&#xa0;years, of which 14 (9.0%) were due to reflux. There were no conversions for malnutrition. Patient satisfaction was high, with an average Likert satisfaction score of 8.4.</p> Conclusions <p>BOAGB continues to show good results as an effective operation at 15&#xa0;years, with a high %EWL and %TWL, low conversion rate, and significant reduction in medication use for hypertension, hyperlipidaemia, and T2D. There was an increase in proton pump inhibitor use at 15&#xa0;years. The operation is durable and weight loss remains excellent. The addition of a SR is effective in reducing long-term recurrent weight gain.</p> Graphical Abstract <p></p>