Introduction: Anti-TNF-α therapy of Crohn's disease (CD) represents considerable progress in inflammatory bowel disease (IBD) treatment; however, many patients still require surgical intervention. The Polish National Insurance Fund currently only covers up to 2 years of infliximab (IFX) therapy in CD patients and 1 year of adalimumab (ADA). Aim: To estimate the effectiveness and side effects of the anti-TNF-α Polish therapeutic program in CD patients. Material and methods: In this retrospective study, medical documentation of 80 CD patients treated with anti-TNF-α (IFX or ADA) was analysed. Fifty-two patients finished 1 year of therapy, and 28 individuals did not complete it due to lack of response to treatment or severe side effects. Results: After treatment, 27 (67.50%) patients achieved a semi-annual remission and 14 (35%) achieved yearly remission. Twenty percent of patients experienced severe side effects such as anaphylactic shock, pneumonia, shingles, or upper respiratory tract infections. A strong negative correlation between the number of patients in remission and the period since therapy termination (r =-0.996, p < 0.001) was found. During the 1-year follow-up, 20 patients were re-enrolled in the biological therapy program (the median time to next therapy was 231 days IQR: 126.5-300.5) Conclusions: Anti-TNF-α treatment in CD is relatively safe. The restricted time period of the therapy affects the clinical course of the disease and entails the need to resume biological therapy.