Device for immobilising injured children in a chair for transporting said children in vehicles by road, wherein said device comprises: one head immobilisation device; one neck immobilisation device; two torso immobilisation devices; a head fastening strap; a torso fastening strap; a leg fastening strap; a carrying and distribution bag for arrangement of elements in sequence of use; wherein the head immobilisation device, the neck immobilisation device and the torso immobilisation devices are built around a core, preferably textile, with high resistance to traction, total flexibility, and do not include any elements which are visible in case of radiological tests; these immobilization devices have a spongy body with an elliptical cross section which is formed by a long, soft and flexible body, with capacity to deform by compression and to recover its initial shape by adapting to the outline it may intercept, if this occurs, during its expansion, without ever loosing elasticity, which will cover the core; this spongy body has a gradual reduction in diameter at the ends of every constituent part so that an approximately thirty-degree angle exists between the edges, having a central area which is thicker than both its ends; the outer body of the head immobilisation device, the neck immobilisation device and the torso immobilisation devices is impervious to liquids and washable; in order to facilitate identification, each immobilization device is a different colour; and the head, torso and leg fastening straps consist of long strips of fabric with high mechanical resistance properties and having a textile element for attachment; these fastening straps are also impervious to prevent the absorption of any liquid from the child who has suffered the accident, and each fastening strap is a different colour; and the carrying and distribution bag for the arrangement of elements in sequence of use is made of a flexible material and also has a closing flap, closure securing mechanism and handles for transportation. one head immobilisation device; one neck immobilisation device; two torso immobilisation devices; a head fastening strap; a torso fastening strap; a leg fastening strap; a carrying and distribution bag for arrangement of elements in sequence of use; wherein the head immobilisation device, the neck immobilisation device and the torso immobilisation devices are built around a core, preferably textile, with high resistance to traction, total flexibility, and do not include any elements which are visible in case of radiological tests; these immobilization devices have a spongy body with an elliptical cross section which is formed by a long, soft and flexible body, with capacity to deform by compression and to recover its initial shape by adapting to the outline it may intercept, if this occurs, during its expansion, without ever loosing elasticity, which will cover the core; this spongy body has a gradual reduction in diameter at the ends of every constituent part so that an approximately thirty-degree angle exists between the edges, having a central area which is thicker than both its ends; the outer body of the head immobilisation device, the neck immobilisation device and the torso immobilisation devices is impervious to liquids and washable; in order to facilitate identification, each immobilization device is a different colour; and the head, torso and leg fastening straps consist of long strips of fabric with high mechanical resistance properties and having a textile element for attachment; these fastening straps are also impervious to prevent the absorption of any liquid from the child who has suffered the accident, and each fastening strap is a different colour; and the carrying and distribution bag for the arrangement of elements in sequence of use is made of a flexible material and also has a closing flap, closure securing mechanism and handles for transportation.