OBJECTIVES: To evaluate the long-term cost-effectiveness of switching from insulin Glargine (IGla) to Insulin Detemir (IDet) in type 2 diabetes patients in the setting of Chinese tier 3 hospitals. METHODS: A published and validated computer simulation model of diabetes (the CORE Diabetes Model) was used to make the long- term (30 years) projection of health economic outcomes. Patient demographic information and clinical endpoints were derived from a subgroup analysis of the PREDICTIVE study. PREDICTIVE was a large, multi-centre, 6 months observational study assessing the safety and efficacy of IDet in everyday clinical practice. HbA1c was reduced of 0.59 % by switching from IGla to IDet. Baseline risk factors and racial characteristic data were obtained from Chinese cohort studies. The market retail prices of medications were calculated to estimate treatment costs. The diabetes management and complications costs were obtained from Chinese published data and adjusted to 2009 values using the Chinese Consumer Price Index. An annual discounting rate of 3% was used for both health and cost outcomes according to the recommendation of Chinese Pharmacoeconomics guideline. One-way sensitivities analysis was performed and illustrated that the results were robust. RESULTS: Conversion to IDet from IGla was projected to improve patient life expectancy by 0.09 year and 0.36 quality adjusted life years (QALYs). Treatment costs, and management costs were increased of 4,004 (84,047 vs 80,043), 243 (28,913 vs 28,670) Chinese Yuan (CNY) respectively. However, the costs of complications including CVD, renal, ulcer/amputation/neuropathy, eye and hypoglycaemia events were reduced by 4,931 CNY (89,628 vs 94,559), resulting in a total direct medical cost saving of 684 CNY when converting to IDet.  CONCLUSIONS: Conversion to IDet from an IGla regimen improved life-expectancy and was a cost-saving treatment approach in a Chinese setting.