Abstract: An automatic pet toilet has a housing defining a generally closed chamber having a floor and side walls, one of the latter having an opening through which the pet can pass. A door is displaceable on the housing between a closed position blocking the opening and an open position clear of same by means of a door drive motor. A closed-door switch on the housing generates an output only when the door is in its closed position. Floor and wall sprays respectively directed in the chamber at the floor and walls of the chamber are supplied with wash liquid, usually water, by a valve connectable to a source of pressurized liquid. A drain in the floor and a chopper connectable to a waste line receive material washed by the sprays from the walls and floor, comminute the material, and feed it to the waste line.