Abstract: A door security device for bracing a door against illegal entry, having an elongated rod member of telescoping rod sections, a reversible foot member pivotally connected to the lower end of the rod member, the upper end portion of the rod member comprising an abutment member for engaging the surface of the door beneath a doorknob, an annular head pivotally connected to the upper end of the rod member for engaging the shaft of the doorknob, and an inelastic linear member threaded transversely of the head and over the doorknob shaft in operative position for securing the head upon the doorknob.