Abstract: The seat unit of a folding pushchair comprises a frame which is provided on each side, on the one hand with a seat-back side member swingably supported at the lower end thereof by the particular rear wheel-strut and stiffening link-rod which is pivotally attached to the lower end of the main supporting arm and, on the other hand, with a connecting-rod pivotally attached at one end to the seat-back side member and at the other end to the upper end of the front wheel-strut. For the purpose of folding the pushchair, the structural design is such as to ensure that, when the main supporting arm and the front wheel-strut withdraw in sliding motion and the rear wheel-strut is swung back against said arm and strut under the tractive force applied by the stiffening link-rod, the seat-back side member and the connecting-rod also return to the folded-back position.