Background: In 2010, Tuscany (Italy) implemented a Chronic Care Model (CCM)-based programme for the management of chronic diseases. The study’s objective was to evaluate its impact on the care of patients with type 2 diabetes. Methods: A population-based cohort study was performed on patients with diabetes, identified by an administrative data algorithm, exposed to a CCM-based programme versus patients not exposed (8486 patients in each group). The groups were matched using a propensity score approach and observed from 2011 to 2014. The outcomes measured were: mortality rate and hazard ratio (HR), hospitalisation incidence rate (IR) (all causes and diabetes-related diseases) and incidence rate ratio (IRR), and Guideline Composite Indicator (GCI) as proxy of adherence to guidelines (IR and IRR). Stratified Cox regression analysis and conditional fixed effect Poisson regression analyses were performed to compute HR and IRR. Results: A significant improvement was observed for GCI (IRR 1.58; 95% CI 1.53–1.62) and for cardiovascular long-term complications (IRR 1.11; 95% CI 1.04–1.18). A protective effect was observed for neurological long-term complications (IRR 0.85; 95% CI 0.76–0.95), acute cardio-cerebrovascular long-term complications—stroke and ST segment elevation myocardial infarction—(IRR 0.81; 95% CI 0.71–0.92) and mortality (HR 0.88; 95% CI 0.81–0.96). Conclusion: The implementation of a CCM-based programme was followed by better management and benefits for the health status of patients. The increase in hospitalisations for cardiovascular long-term complications could engender cost-efficacy issues, but a better integrated care (GPs and specialists) and a more appropriate specialist outpatient services organisation could avoid a part of these, while still maintaining the benefits seen.