Abstract: A backrest for vehicle seats, has a backrest frame, a backrest cushion which is fastened thereto and consists of a cushion layer and of a ventilation layer which covers the cushion layer and through which air can flow. A fan is provided for the active ventilation of the backrest cushion. For the purpose of improving the sitting comfort, the vehicle seat is equipped with a lordosis support, the fan being fastened largely centrally in the cushion area on the lordosis support at low vibrations. The fan is situated inside an air duct constructed in the cushion layer, the clear cross-section of the air duct being dimensioned such that the fan remains inside the air duct during its movement going along with the lordosis adjustment.