Psoriatic arthritis (PsA) is a chronic, immune-mediated, systemic disease affecting less than 1% of people with variations by parts of the world, and around 20%-30% of participants with psoriasis. Upadacitinib (RINVOQ) is approved drug for the treatment of adult participants with active PsA in Europe. Approximately 450 adult participants who are prescribed Upadacitinib by their physician in accordance with local label will be enrolled in 4 countries in Europe: France, Germany, Greece and Italy. Participants will receive upadacitinib as prescribed by their physician according to their routine clinical practice and local label. Participants will be followed for up to 24 months. There is expected to be no additional burden for participants in this trial. Participants will attend regular visits during the study at a hospital or clinic according to their routine clinical practice.