OBJECTIVES:  To assess the cost-effectiveness of infliximab as induction therapy (3 doses) for the treatment of severe active ulcerative colitis, i.e. exacerbations requiring hospitalization in adult patients with an inadequate response to conventional therapy including intravenous glucocorticoids, compared with surgery (colectomy) in Poland. METHODS:  This study used the decision tree model which was positively received by NICE and adjusted to Polish settings. Efficacy parameters were based on clinical trials: Jarnerot 2005, Sands 2001, Lichtiger 1994 and D'Haens 2001. Twelve-month time horizon was developed. Cost data specific for the Polish health care system was based on retrospective medical record review of patients with ulcerative colitis. Resource use associated with the surgery was based on clinical expert opinion. The unit costs of treatment were derived from Polish official tariff lists for health care services paid by public payer. Average body weight of the patient (60 kg) was based on data from registry of patients with Crohn’s disease, assuming the similar nature of the disease. RESULTS:  Infliximab was associated with a gain of 0.21 quality adjusted life years (QALYs) compared with colectomy. Additional costs associated with the biological treatment were estimated at 14,793 PLN. Incremental cost-utility ratio was estimated at 69,984 PLN/QALY for infliximab compared with colectomy. The sensitivity analysis showed a relative consistency of results. CONCLUSIONS:  The estimated cost per QALY is much below official threshold (99,543 PLN/QALY) which indicates that treatment with infliximab is cost effective compared with surgical treatment in Polish conditions.