Abstract: A collapsible screening device such as an insect screen for an opening in a wall, particularly for a window or door, comprises a frame structure composed of an elongate base member accommodating a screening in a first retracted position, two side members pivotally connected with opposite ends of the base member, so as to be collapsible from an erected position at substantially right angles from the base member into a collapsed position parallel and close to the base member, and a separate bar member of a length substantially equal to the length of said base member. A free end of each side member and opposite ends of the separate bar member are formed with releasably interlocking assembling means to provide a stable connection in an assembled condition of the frame structure.