Abstract: A window safety guard is used for preventing an intrusive person or object from entering a home through a window when it is left open by the owner. It is also easily removable during emergency situations as it has a simple locking mechanism and may be removed as a single unit. The assembly has a series of vertical bars with tapered ends that are inserted into corresponding holes in a windowsill and in a bottom frame edge of a raised lower window. Support bars are coupled to the vertical bars to add strength and to help block the window opening. The window safety guard assembly also has a locking mechanism wherein a small rod is inserted in a corresponding hole in a side edge of an upper window frame. The small rod, when inserted, is also abutting the top frame edge of the raised lower window to prevent the lower window from being raised and the window safety guard from being removed.