Fecal incontinence (FI) is one of the most psychologically and socially debilitating condition in an otherwise healthy individual. Sacral Nerve Stimulation (SNS) is the option in cases where conservative treatments have been ineffective and before undergoing surgery procedures like dynamic graciloplasty or artificial anal sphincter in patients with intact anal sphincter (IAS) and before Sphincteroplasty in patients with structural deficient anal sphincter (SDAS). Interstim® is a relatively new effective and safety therapy that has shown to be more effective than surgery in almost all patients. OBJECTIVE: To asses the efficiency of introducing Interstim® in management of patients suffering FI in the Spanish setting using a cost-effectiveness model. METHODS: A decision analytic model was developed to estimate the costs and outcomes of patients with FI managed with and without Interstim®. Clinical and economic data were retrieved from published studies and an expert panel. The analysis was run over a 5 years time horizon from a NHS perspective and the primary outcome was quality-adjusted life years (QALYs). Cost data were obtained from SOIKOSTM Spanish's health care costs database. Costs and benefits were actualized to euros 2004 and discounted at 3% annum. Sensitivity analyses were performed in order to handle uncertainty. RESULTS: Preliminary results show that the introduction of Interstim® in the management of FI increases treatment costs in 1,211 in IAS patients and 1,024 in SDAS patients (5,246 to 6,456 and 7,648 to 8,671 respectivelly), yielding to improvement in quality adjusted life expectancy of 0.234 and 0.228 respectivelly. Discounted cost per QALY gained of the introduction of Interstim® are 5,182 and 4,486. CONCLUSIONS: The use of Interstim® as an alternative to current surgical procedures in certain circumstances (as second or third treatment line in IAS and SDAS IF patients) is associated to an improvement of IF patients at a reasonable extra cost.