Abstract: A seat for use in a motor vehicle has a body supporting unit and a back rest which is pivotably connected to the body supporting unit by two hinges having pintles provided with eccentrics which cause the back rest to perform a composite pivotal and transverse movement while it changes its orientation with reference to the body supporting unit. The back rest carries two pivotably mounted arm rests which are connected to the back rest and to the body supporting unit by linkages serving to ensure that the orientation of the arm rests remains substantially or completely unchanged while the back rest is pivoted with reference to the body supporting unit. A second linkage can be used to pivot the front ends of the arm rests rearwardly and upwardly when the back rest is lifted with reference to the body supporting unit and is pivoted forwardly toward the dashboard in a two-door motor vehicle in order to afford convenient access to the rear seats or to permit a passenger to leave a rear seat with a minimum of effort.