A skateboard ski apparatus wherein a skateboard platform and related skate trucks are combined with removable ski shoes, the ski shoe having a substantially flat body member provided on its lower surface with parallel runners, and on its upper surface with support ribs adapted to either receive wheels of an existing skateboard or the axles of the wheel-truck assembly. The forward end of the preferred arrangement of the ski shoe includes an upwardly turned end to allow the apparatus to slide over the snow. A second arrangement includes a ski shoe having both ends adapted with upturned ends so that the skateboard ski can be used in either a backward or forward direction.