A self-cleaning filter assembly for use in a solenoid-actuated valve of the type having fluid pressure-operated diaphragm to control opening and closing of the valve, the diaphragm operating in response to fluid pressure admitted from the inlet chamber of the valve into a control chamber to maintain the valve in a closed position, and when the fluid pressure in the control chamber is relieved by actuation of the solenoid, to open the valve. The self-cleaning filter assembly filters control fluid admitted to the control chamber, and comprises a filter element cleaned by a brush each time the valve is opened or closed, thereby to prevent clogging of the filter during use.