The ski boot (1) comprises a sole (9) which is connected to the ski and a collar (4) pivoted on the heel (5) fixed to the sole, The axis (20) of the pivot (18) is situated in a longitudinal plane of the boot and oriented horizontally. The boot has asymmetric stops for limiting angular displacement of the collar.The collar has an internal lateral extension which fits in the lateral wall of the heel in order to limit outward angular displacement of the collar. This outward angular displacement of the collar is in a range between zero and 20 degrees. Zero displacement corresponds to the vertical position of the collar. Only the stops limit angular displacement of the collar towards the interior of the boot. The heel zone situated on the outside of the boot is higher than the zone situated on the interior side of the boot.