A side guard or lateral protection arrangement for motor vehicles, wherein at least one reinforcement, extending substantially in the longitudinal direction of the vehicle, is arranged within each of the side doors. The reinforcements are braced in case of a force effective in the longitudinal direction of the vehicle, with each end directly or indirectly against a component fixedly mounted to the vehicle or against a further reinforcement associated with an adjacent door. This bracing takes place in the longitudinal direction of the vehicle. The reinforcements are axially adjustable in their lengths so as to bridge a space between an end of the reinforcement means and the component fixedly mounted to the vehicle or further reinforcement, which space results from manufacturing tolerances in the construction of the motor vehicle.