Optimising glycaemic control and reducing risk of associated co-morbidities in the patient with complex diabetes and obesity presents a number of challenges in primary care. This study evaluates weight and HbA1c changes at 12 months (primary outcomes) and blood pressure, lipid and medication changes (secondary outcomes) in people with diabetes referred by the diabetes specialist practice nurse (DSN) to a weight management group. The DSN identified patients who would benefit from the weight management intervention (Slimming World, SW) held within the practice setting. Referred patients attended the funded weekly group sessions for up to 12 weeks. On completion, patients were offered a second 12 week referral, if they had achieved a ≥3% weight loss, to attend a locally run SW. The DSN recorded age, gender and baseline data for weight, height, HbA1c, systolic and diastolic blood pressure (SBP & DBP), total cholesterol (TC), LDl cholesterol (LDlc), HDl cholesterol (HDlc), triglycerides (TG) and medication. These measures were then repeated at 36 months and 12 months post intervention. A post-intervention questionnaire determined how useful patients found the group, the support they received, accessibility of the group and dietary and lifestyle changes. Sixty-nine patients, mean age 60.5 (10.05) years, achieved a mean weight loss of 5.5 (5.16) %, reduction in BMI (37.7 (6.11) to 35.9 (6.30) kg/m2, P<0.001) and HbA1c levels (62.8 (12.85) to 55.0 (13.02) mmol/mol, P<0.001) at 12 months. 81.2% of patients reduced their HbA1c levels. Small reductions were observed in BP and triglycerides with six patients reducing their diabetes medications. Twenty patients completed the questionnaire: 95% found the intervention/support very useful and 80% the group accessible. Unhealthy snacking habits reduced (P<0.001) and going for walks increased (P<0.001) with fewer people avoiding moderate activity (P<0.05). Despite being a chronic, progressive condition, this service evaluation found that referral from primary care to a community based weight management programme was successful in supporting patients with established diabetes to improve their diet and physical activity levels and lose weight and improve their glycaemic control 12 months later. Improvements in cardiovascular risk factors with some patients being able to reduce their medication were also seen.