OBJECTIVES: The aim of this study was assessing cost-utility of infliximab compared with current treatments in patients with moderate to severe ulcerative colitis (UC) in Iran. METHODS: We constructed a decision tree model with 5 year time horizon to follow up 1000 hypothetical patients for estimating treatment costs and outcomes. Patients were individuals with moderate to severe UC that is resistant to current treatments. Remission rate, clinical response and surgery were selected as clinical outcomes. Then for estimating QALY, utility value related to each state drive form published literature. We also estimated associated probabilities using patients ‘medical records and specialists’ opinion.  Costs of treatment including physician visits, laboratory tests, hospitalizations, surgery and drugs were estimated based on the public and private sector tariffs and drug price list that set by pricing committee of food and drug administration. Infliximab costs at dosage of 5 mg /kg were calculated for UC patients with average weight of 75 kilogram. RESULTS: Incremental cost-utility ratio of infliximab treatment in UC patients estimated with public and private sector tariffs were 18 260 and 188 366 dollars per QALY gained compared with current treatments, respectively. CONCLUSIONS: According to recommendation of world health organization for choosing cost effective intervention, interventions with relative cost effectiveness  value  less than 3 time of gross domestic production per capita are cost –effective. So for UC patients, our finding indicates that ICUR values with public and private sector tariffs are more than 3 time of local GDP per capita, 3.8 and 39.5 respectively and infliximab treatment is not cost effective.