A cross-country ski binding comprises a toe iron which has two side portions, which extend substantially at right angles to the tread and engage at least one portion which projects from the sole of the skiing boot in front of its toe portion. A clamping member serving to retain the projecting portion is pivoted at least at one end to one side portion. In position for use, the clamping member extends transversely to the longitudinal direction of the ski. The clamping member is pivotally movable in a plane which is transverse to the longitudinal direction of the ski. At its other end, the clamping member is adapted to be releasably locked to the other side portion of the toe iron. In a top plan view, the toe iron has a constriction which is disposed in front of the tip of the foot and which is preferably narrower than the foot. The portion which projects from the sole has a recess which registers with the constriction.