OBJECTIVES: Dapagliflozin is a sodium glucose co-transporter 2 (SGLT2) inhibitor approved for the treatment of adults with type 2 diabetes (T2DM). This study compared the cost-effectiveness of dapagliflozin versus a sulfonylurea (SU) added to metformin in persons with T2DM inadequately controlled on metformin alone in Colombia. METHODS: A discrete event simulation model (Cardiff diabetes model) based on UKPDS 68 was used to simulate disease progression and to estimate the economic and health treatment consequences in people with T2DM. Epidemiologic and clinical efficacy parameters were obtained from the literature. The cost of medication was obtained from country level price data, SISMED and Farmaprecios; the cost of macro- and microvascular events was based on POS tariffs, SOAT Manual and consultation with a local expert. Costs were expressed in US dollars [Exchange rate: 1,790.6 Colombian pesos = 1$]. A 20-year time horizon was assumed. Costs and health outcomes were discounted at 3% annually. Deterministic and probabilistic sensitivity analyses (PAS) were performed. RESULTS: The total direct cost of the dapagliflozin + MET group over 20 years was higher than that of the SU added to metformin group ($11,482,424 vs. $8,942,315). Treatment with dapagliflozin resulted in a greater number of quality-adjusted life years (QALYs) compared to SU combination (10,861 vs. 10,439).The calculated Incremental Cost-Effectiveness Ratio (ICER) for dapagliflozin compared to SU was $ 6,023 per QALY gained. Using WHO's criteria, dapagliflozin compared to SU treatment strategy has a 85% probability of being highly cost-effective (ICER< 1 GDP per capita) and 100% probability of being cost-effective (ICER ≤  3 GDP per capita).The results were robust to sensitivity analysis. CONCLUSIONS: This study demonstrated that dapagliflozin in combination with metformin would be a cost-effective treatment option for patients who are inadequately controlled with metformin monotherapy in Colombia.