An article of sports footwear (10) comprises an upper part or casing (11) to partly surround the user's foot, and a sole (12), associated with the casing (11). The sole (12) comprises an internal insole (13) having, during use, an upper surface (13a) attached to the casing (11) and a lower surface (13b) to which at least an anti-slip support element (14), made of an at least partly soft material, is attached. The insole (13) has a plurality of stiffening elements (15) made of a harder material than that of the anti-slip element (14), and disposed in correspondence with the position of the sole (12) where the front bindings (19) and/or back bindings (20) of the skis act. The stiffening elements (15) are inserted in gaps and spaces present in the anti-slip element (14) so as to be disposed slightly retracted with respect to the at least one anti-slip support element (14) in a non-deformed condition of the latter, as for example when in use for walking, and being able to be disposed at least flush therewith in the deformed condition of the anti-slip element (14), for example when in use for skiing.