A self-cleaning litter box is disclosed which provides various advantages over the prior art. In particular, in one embodiment, the self-cleaning litter box is configured to use a cartridge which may include a litter compartment and a waste compartment. In another embodiment, the cartridge may be non-compartmentalized. The cartridge may be disposable, thus eliminating the need for the user to clean the litter tray and handle heavy litter containers. In other embodiments, the system includes a rake assembly configured with a drive assembly that is protected from contamination. In accordance with another embodiment of the invention, the self-cleaning litter box is configured to be used with all types of litter including crystal type litter.