Abstract: A pet litter box apparatus includes an outer enclosure having a front opening for access by a cat or other animal, with an inner carrier providing a litter accumulation area and including a radially-extending screen, rotationally mounted within the outer enclosure on a carrier support at a hub. A waste storage container with a normally closed access port is positioned below the hub. For cleaning, the carrier is rotated about the hub on its axis of rotation to move the screen through the litter accumulation area to collect any agglomerated litter and fecal material. This waste is carried by the screen in the rotating carrier to a point above the hub, where a shield on the hub normally covering the access port for the waste storage container has now rotated to expose the access port and enable the agglomerated litter and fecal material to fall into the waste storage container.