A disposable insert for a pet litter box is designed to fit inside a conventional litter box or other enclosure used for receiving wastes from pets and domestic animals. The insert comprises two nested containers, the inner of which contains the pet litter. Between the two containers is tucked a waste bag with projecting tabs that can be pulled to unfold the bag so that the bag encloses the inner container and its soiled litter and can be used to lift the insert and remove it from the litter box for disposal.
