Abstract: A system for protecting motor vehicle occupants against injury in side collisions comprises first reinforcing members arranged between the exterior and interior panels of the vehicle body sides and/or doors and second reinforcing members incorporated in the vehicle seats, the members extending transversely to the vehicle and disposed to transmit, after a certain deformation of a press-loaded body side or door, the load to the floor of the vehicle and to the opposite body side or door. The first reinforcing members are made as essentially plastically deformable, energy absorbing members extending transversely over at least the greater part of the space between the exterior and interior panels of the body sides and/or doors and which vertically cover an area level with the bumpers of the vehicle.