OBJECTIVES:  To project long term costs and outcomes for continuous subcutaneous insulin infusion (CSII) compared with multiple daily injections (MDI) of insulin in adult type-1 diabetes mellitus (T1DM) patients in Italy from the National Health Service (NHS) perspective. METHODS: The CORE Diabetes Model (CDM) was used to determine the incremental cost-effectiveness ratio (ICER) of CSII compared with MDI among adult patients with T1DM in Italy. The primary input variable was change in HbA1c and assumed to be a 1.2% improvement for CSII as compared to MDI in a cohort of Italian T1DM patients with an average HbA1c baseline value of 8.95%. It was also assumed that CSII patients had 50% less hypoglycemic events compared with MDI patients. A series of Markov constructs simulated the progression of diabetes-related complications. The average annual cost for CSII and MDI were €5699.20 and €2734.71, respectively. The costs  were derived from Italian-specific sources and other published data. A 60-year time horizon and a discount rate of 3.0% per annum on costs and clinical outcomes were used.  RESULTS: Treatment with CSII was associated with improvements in life expectancy of 0.981 years vs. MDI and quality adjusted life year (QALY) of 1.063 years vs. MDI with corresponding ICERs of €34,541 per life-year and €31,879 per quality-adjusted life year (QALY) gained for CSII compared with MDI.  The cumulative incidence of end-stage renal disease (ESRD) was reduced by 18% (RR=0.816) with a NNT of 22 patients to avoid one case of ESRD.while cumulative incidence of peripheral vascular disease (PVD) was reduced by 14% (RR=0.856); with a NNT of 46 patients to avoid one case of PVD.  CONCLUSIONS: Setting the willingness to pay at €40,000/QALY (based on a £30,000 NICE threshold), CSII is a cost-effective treatment option when compared to MDI for adult patients with T1DM in Italy.