Abstract: An adjustable, removable child window guard includes a first panel, a second panel and a bolt and slot arrangement for slidably connecting the first panel to the second panel. A locking mechanism requiring two-handed operation to permit the relative sliding movement of the first and second panels is provided for selectably permitting and inhibiting relative sliding movement of the first and second panels. The window guard includes two sets of teeth affixed to the first panel and two sets of tooth engagement means mounted on the second panel. L-shaped brackets are provided to permit non-intrusive mounting of the window guard in a window frame.