A brace for immobilising a traumatized or operated shoulder including: at least one cushion configured to at least partly adhere to the body of a user having a traumatized or operated shoulder to be immobilised; at least one arm support sling extends from the cushion and with it delimits a compartment for housing a forearm of the user corresponding to the traumatized or operated shoulder; at least one abdominal band configured to envelope and/or surround at least one abdominal and lumbar area of the user; at least one support harness engaged to the cushion to support the cushion at a predetermined position and level. The support harness includes at least one rest portion configured to engage at least one shoulder of the user to support the cushion and the arm support sling. The support harness is configured to engage, resting thereon, the user's traumatized or operated shoulder.