Abstract: A locking door threshold having an elongated vertical slot within the upper surface, an elongated striker bar received in the slot, the striker bar being vertically slidable within the slot between a lower position and an upper position in which the striker bar intercepts a door pivoted over the threshold, and a slide bar positioned within the slot and below the striker bar, the slide bar being horizontally slidable between a first and second position, the surfaces of the slide bar and the locking bar interrelating so that when the slide bar is in one position the locking bar is elevated to prevent opening of the door and when in the second position the locking bar is vertically lowered in the threshold slot to permit the door to be opened. A locking lever extending from the threshold and connected to the slide bar is used to control the position of the slide bar.