Abstract: An automatically releasable ski binding unit has heel and toe binding units mounted to a common mounting platform, the toe unit being rotatable about an axis transverse to the longitudinal direction of the ski. A guide attachable to a ski is configured to slidingly captively accept the mounting platform for movement along the longitudinal direction of the ski. Rotation of the toe mounting unit from a normal to an upwardly extending position facilitates stepping into and out of the binding. A locking system provides for locking the mounting platform to the guide at a variety of chosen positions, the locking system being releasable by rotation of the toe binding unit towards the ski from the normal position adopted where a ski boot is inserted and the binding is locked. The heel release has a rear sole-engaging portion which is urged to the rear by the heel of an inserted ski boot during the locking operation.