Behet's syndrome (BS) is a systemic autoimmune vasculitis that can affect multiple organs, including the skin, eyes, and vascular system. Refractory BS poses significant treatment challenges, necessitating novel therapeutic approaches. Upadacitinib, a selective JAK1 inhibitor within the JAK-STAT pathway, has shown promise in modulating immune responses. This study aims to evaluate the efficacy and safety of upadacitinib in patients with refractory BS.