Objective: PREDICTIVE was a large, multi-national, observational study assessing the safety and efficacy of insulin detemir (IDet) in real life clinical practice. The aim of this health economic study was to assess the cost-effectiveness of Idet and Insulin aspart (IAsp) versus human soluble insulin (HSI) and neutral protamine Hagadorn (NPH) in patients with type 1 diabetes, based on the Czech sub-cohort of the PREDICTIVE study. Methods: A published and validated computer simulation model was used to project long-term economic and clinical outcomes in a simulated cohort of type 1 diabetes patients treated with either IDet and IAsp or HSI and NPH, in a Czech setting. Probabilities of complications and HbA1c-dependent adjustments were derived from the PREDICTIVE trial. Complication and treatment costs were obtained from Novo Nordisk s.r.o. and projected over patient lifetimes from a societal perspective in the Czech Republic. Future costs and clinical benefits were discounted at 5% per annum. Results: IDet + IAsp versus HSI + NPH treatment was projected to improve life expectancy by approximately 0.17 years (11.52±0.14 versus 11.35±0.13 years) and quality-adjusted life expectancy by 0.70 quality-adjusted life years (QALYs) (6.97±0.09 versus 6.28±0.08 QALYs). Treatment and complication costs associated with IDet + IAsp treatment were projected to be lower over patient lifetimes than with HSI + NPH (Czech Crowns (Kè) 921,722±38,714 versus Kè 1,145,728±38,599 per patient, difference Kè -224,006). IDet and IAsp were associated with a delay to the onset of any diabetes-related complication by a mean of 0.17 years (0.77 versus 0.60 years). Conclusion: A Czech sub-analysis of data from the PREDICTIVE study has demonstrated cost and clinical benefits for patients with type 1 diabetes. IDet + IAsp treatment was projected to be associated with improvements in life expectancy, QALYs and was cost saving compared to NHP + HSI in the Czech setting.