OBJECTIVES: The purpose of this study was to assess the cost-effectiveness of drotrecogin alfa (activated) (DAA) as an adjunct to standard therapy compared to standard therapy alone for Swedish patients with severe sepsis by using 1) country specific cost and resource data compared to 2) exchange rate transferring of a UK model application based on the results from the clinical trial and UK treatment patterns. METHODS: In the PROWESS trial DAA has been found to decrease the all cause 28-day mortality in adult patients with severe sepsis. A C/E model was developed for estimating costs and outcomes and could be applied taking account of local treatment patterns, costs, life expectancy, and discount rates. Patients with both an infection and at least one acute organ dysfunction diagnosis (ICD-10) recorded were selected from Huddinge university hospital in Sweden (n = 55). Direct costs for drugs, intensive care, and general wards up to 28 days, and to final discharge were determined according to the hospital resource and cost assignment system (2002 prices). The cost of DAA was based on the average use in the trial and the Swedish price 2002. RESULTS: The cost-effectiveness ratio of an adjunct drotrecogin alfa (activated) compared with standard therapy alone in the base case including patients with failure in at least two organs was €19,500 per QALY based on Swedish data. The corresponding figure was €13,700 when results were transferred by the exchange rate. Higher ICU costs in Sweden compared to UK account for 45% of the difference whereas higher life expectancy among the UK patients account for 55%. CONCLUSIONS: Drotrecogin alfa (activated) is cost-effective when compared to other accepted Health care interventions in Sweden. Local data application is important but does in this case not change the overall conclusion.