Abstract: The present invention 10 discloses a louvered window insert comprising two louvered frame sections 39, 50 each having one vertical member 44, 60 with an upper and lower horizontal member 40, 42, 56, 58 extending from each end thereof and a plurality of louver blades 46, 52 extending horizontally therebetween. The distal ends of the horizontal members and louver blades of the first section have recesses 48, 54 to receive and slidably secure the horizontal members 56, 58 and louver blades 52 of the second section as they travel therethrough allowing a user to size the insert to a window 12 simply by placing the fully overlapped assembly inside an open window 12 and separating the two frame sections 39, 50 thereby reducing the overlap of the horizontal members and the louvers and effectively elongating the insert until the two vertical members 44, 60 are flush to their respective side jambs and then lowering the window 12 until it sits atop the present invention.