Psoriasis is one of the most common dermatological diseases that affects about 5% of the world’s population. The disease occurs in all age groups, it is often characterized by continuously-recurrent course and significantly worsens patient’s quality of life. Despite the numerous studies conducted in different countries around the world, the pathogenesis of the disease has been studied insufficiently. Currently, immune system regulation disorders realized through complex mechanisms of keratinocyte interaction with the cells of the congenital and adaptive immunity system are believed to play the main role. Further, the severity and outcome of the disease depend on the severity of immunological disorders and imbalance of cytokine regulation of intercellular interactions. Immunological preparations are the main therapy for psoriasis and its most severe form, psoriatic arthritis. Genetically engineered biological preparations, monoclonal antibodies, specifically blocking certain pro-inflammatory cytokines or immunocompetent cells, are the most modern of them. This group of drugs is used in the case of severe psoriasis, especially in combination with joint diseases, and ineffective conventional therapy. Implementation of innovative biological preparations in the treatment regimen for patients with psoriasis enabled significant prolongation of disease remission and made a breakthrough in dermatology.