OBJECTIVES: Type 2 diabetes (T2D) patients on basal insulin with uncontrolled HbA1c levels often receive an add-on with bolus insulin to lower HbA1c levels. The aim of this analysis is to estimate long-term cost-effectiveness of treating T2D patients with – a recently introduced – twice daily (BID) exenatide add-on to basal insulin strategy from a Turkish health care perspective. METHODS: Clinical inputs for both treatment strategies were taken from the GWDM clinical trial. The strategies were assessed using a micro-simulation disease model (CARDIFF). The model predicted micro-and macro-vascular complications based on the UKPDS equations. The incidence of adverse events, diabetes related complications and changes in body weight yielded estimates of health care costs and health utilities. The direct (T2D and complication) costs in the model reflect the Social Security Institution costs. Discounting both costs and effects at 3% over the 40 year follow-up of the model, resulted in life time estimates of costs and quality-adjusted life years (QALYs) on both treatment strategies. Deterministic and probabilistic sensitivity analyses, as well as elaborate scenario analyses were performed. RESULTS: Results showed that exenatide treatment significantly improves QALYs by 0.60 (95% CI: 0.24 to 0.97). Health effects were reached at an additional cost of 217 $ (95% CI: -356$ to 976$), resulting in an incremental cost-effectiveness ratio of 362 $ per QALY gained. Scenario analyses showed that these results were robust to changes in input parameters. At a willingness-to-pay threshold of 30,000 $/QALY the exenatide strategy had a near 100% probability of being cost-effective compared to bolus insulin. CONCLUSIONS: A twice daily exenatide add-on to basal insulin treatment for T2DM patients with uncontrolled HbA1c levels is considered a highly cost-effective strategy from the Turkish public healthcare perspective.