Abstract: The present invention is directed to a window of the tilt and turn type which may selectively be positioned in a locked condition wherein the window member is in coplanar alignment with the frame; in a vent position whereat the window is tiltable about a horizontal axis adjacent the lower edge thereof; and a casement position whereat the window may be pivoted about a vertical axis, as for cleaning. The device is characterized in that the operating mechanism controlling the various conditions of operation of the window is provided with safety interlock means whereby the window may not be dislodged from its normal operating conditions by inadvertent or improper actuation of the operating handle.