The ABUHB level 3 adult weight management service provides individualized 2-year multidisciplinary support for patients with severe obesity and associated multi-morbidity. Some patients are discharged before 2 years or voluntarily leave the service early. To date, this service has received >400 referrals from 5 local authority areas as well as out-of-area referrals. The prevalence of adult obesity (BMI≥30.0 kg/m2 and ≥40.0 kg/m2) in the ABUHB area is approximately 25% and 2.5% respectively. Between February 2013 and May 2019, 267 (67.9%) female (mean age±S.D., 45.6±12.1 years) and 126 (32.1%) male (47.4±12.4 years) patients attended initial assessment. Most were of White ethnicity (˜98%) and 31.5% lived in areas that are in the lowest 20% of multiple deprivation (Welsh Index of Multiple Deprivation). Mean bodyweight and BMI were 149.1±34.5 kg and 52.7± 10.5 kg/m2, with no gender difference in BMI (−1.7 kg/m2, 95%CI: −3.8, 0.7; P=0.169). The frequencies of class I, II and III obesity were 1.0%, 6.6% and 92.4%. Every patient had a waist circumference greater than recognised cut-offs for females (88 cm) and males (102 cm). In patients who had been in the service for at least 2 years (n=265), after imputing missing data (38.5%) with the last observation carried forward method, at 1-year follow-up 35.8% lost <5% of their bodyweight, 18.1% lost 510% and 11.7% lost >10%. Mean weight loss at 1-year was 4.35 kg (95% CI: −5.45, −3.25; P<0.001). At 2-year follow-up (60.8% missing data), 34.7% had lost <5% of their bodyweight, 15.5% had lost 510%, and 13.2% had lost >10%. Mean 2-year weight loss was −4.50 kg (95% CI: −5.86, −3.14; P<0.001). Analysis of complete data produced mean weight changes at 1-year (n=163) and 2-years (n=104) of −6.10 kg (95% CI: −7.51, −4.69; P<0.001) and −6.21 kg (95%CI: −8.87, −3.55; P<0.001). At 2-years, the maximum individual weight loss was −53.3 kg. These results show an individualized MDT weight management service, with many patients from socially disadvantaged communities, is an effective weight loss intervention for patients with severe obesity. This evaluation is part of on-going work to improve this service.