OBJECTIVES: Rare diseases such as ulcerative colitis (UC) have significant impact on patients and their families, as well as the healthcare systems and societies. The high costs of medicines makes actual researches in this field. The main aim of this study was to perform budget impact analysis of using combination of biologics - infliximab + golimumab in equal proportions. METHODS: Analysis of the published clinical trials was conducted to evaluate comparative efficacy and safety of the using of different types of biologics therapies – infliximab, golimumab. To measure costs of ulcerative colitis for the state budget were used “cost of illness” and “budget impact” analyses.  Direct medical costs included diagnosis, treatments, medications, blood and its components, nutrient mixture and were calculated for 1 year-therapy. In this study were performed 2 variants of UC treatment costs, in 1^st variant was used infliximab, in 2^nd variant - infliximab + golimumab in equal proportions. RESULTS: According to published trials golimumab was provided efficacy similar to infliximab in inducing and maintaining clinical remission, clinical response, and mucosal healing. Loss of response was occurred in approximately 30% of patients, leading to discontinuation of biologic therapy and/or colectomy. So using the combination of biologics was preferred. The mean annual overall direct health care cost of UC treatment for 1 patient with infliximab was estimated to be 456 000 rubles ($ 8 514), and with infliximab + golimumab in equal proportions – 533 256 rubles ($9 957). Thus budget impact of using combination of 2 biologics - infliximab + golimumab in equal proportions was estimated to be 14%. CONCLUSIONS: Golimumab was provided efficacy similar to infliximab and the use combination of 2 biologics infliximab + golimumab in equal proportions for treatment UC has little effect on the budget.