Biological therapy (infliximab and adalimumab) in inflammatory bowel diseases is based on the IgG1 anti-TNF monoclonal antibodies with potent anti-inflammatory effects whose main mechanism of action is thought to be the induction of inflammatory cell apoptosis. Unquestionably, which arises from the most recent studies and meta-analysis, anti-TNF angents are an effective therapy primarily for the treatment of Crohn's disease, but also ulcerative colitis, in different clinical situations. Infliximab has the most extensive clinical trial data, but other biological agents, such as adalimumab and certolizumab pegol appear to have similar benefits. In terms of future research, more long-term data are needed for both certolizumab pegol in Crohn's disease and adalimumab in ulcerative colitis. Important role in the application of biological therapy is assessing its effectiveness and cost-benefit relationships that are estimated by regular follow-up. In the absence of response (primary and secondary) therapeutical options are dose increase, giving the drug in shorter intervals and substitution with other biological drug.