Sports footwear, in particular to a ski boot, having an adjustable rear spoiler is provided. The spoiler is connected by respective connecting elements to the side elements attached to or integral with the cuff of the sports footwear and the distance of the connecting elements from each other can be adjusted by acting on a single, common adjusting device. Thus, adjustment of the volume inside the cuff, which receives the ankle and the lower portion of the calf of a user, takes place in an extremely simple and quick manner and without the risk of asymmetries in the adjustment.