Psoriasis is a chronic infl ammatory skin disease aff ecting about 2-3% of the world population, and around 1.6% of the population in Croatia. Nowadays, psoriasis is considered to be a multisystemic infl ammatory disease with a variety of comorbidities such as hypertension, diabetes, cardiovascular diseases, infl ammatory bowel and eye diseases, and psychosocial comorbidities. Th e most common comorbidity in psoriasis is psoriatic arthritis, aff ecting about 30-40% of patients, although accurate epidemiological data are not available. Nowadays, the new paradigm of psoriasis and psoriatic arthritis uses the term psoriatic disease with skin and/or musculoskeletal manifestations. Contemporary treatment of psoriasis relies on evidence-based medicine including clinical experience, scientifi c evidence, but also patients’ desires when choosing the appropriate therapy. Biological therapy in the treatment of psoriasis represents a signifi cant progress compared to classical psoriasis therapy, due to the high effi cacy and safety of new drugs.