Immobilization device (1) comprising a first and a second immobilization unit (2, 3). The first immobilization unit (2) comprises a base on which is disposed a first locking unit (4) to immobilize the skull-cervical area and a second locking unit (5) to immobilize the thoracic-abdominal area. The second immobilization unit (3) is suitable for receiving and fixing the first immobilization unit (2), which comprises a third locking unit (6) to immobilize the patient from the waist down. The second locking unit (5) also comprises two rigid or semi-rigid flaps (9), preferably arched, fitted on each side of the base in a pivoting and/or detachable manner, said flaps (9) being suitable for surrounding and immobilizing the abdomen and/or thorax area. To keep the patient in the immobilized position the immobilization device (1) comprises a plurality of fixing means (7).
