Summary: Biologics used in patients with inflammatory bowel diseases are mostly inhibitors of the tumor necrosis factor (TNF-a). In recent years they have been proven to be effective in achieving and maintaining clinical and endoscopic remission both in patients with Crohn’s disease and ulcerative colitis. Since 2013, biosimilar medicines, i.e. medicines of similar quality, safety and efficacy to already approved reference preparations, have been used to treat patients with inflammatory bowel diseases. Recently published research results indicate that the efficacy and safety profile of biosimilars is not different from the results obtained in the treatment of patients with the use of reference drugs. Considering the much lower cost of treatment with biosimilars, more patients can be treated with these unique therapies than before.