Abstract: A weatherstripping kit for sliding windows that are installed within opposing window channels defined by side channel walls, for movement parallel to an adjacent stationary panel. The kit includes a pair of first elongated weatherstripping holders for attachment to the side channel walls of opposing channels for holding weatherstripping in contact with the sliding window for providing a seal between the channel walls and the window over the width of the window when the window is closed. The kit also includes a second elongated weatherstripping holder for attachment to the sliding window at the end of the window adjacent the stationary panel for holding weatherstripping in contact with the stationary panel for providing a seal between the sliding window and the stationary panel over the length of the sliding window.