The invention concerns detergent dosing devices and particularly a device for metering detergent doses within a dishwashing machine. A detergent dosing device in accordance with an embodiment of the invention comprises: a water/wash liquor collection area (12), a controlled inlet valve (14) for receiving water/wash liquor from the water/wash liquor collection area (12) and selectively allowing the collected water/wash liquor to pass through it, a housing part 10 for receiving water/wash liquor passed to it by the controlled inlet valve (14), a detergent supply (16) for mixing with said water/wash liquor, a first sensor (18) for sensing the cleanliness level of water/wash liquor, a second sensor (20) for sensing detergent, a controller (22) for receiving signals from said first and second sensors (18, 20) and for selectively controlling said inlet valve (14) on the basis of the outputs from the first and second sensors and an outlet (28) for dispensing mixed water/wash liquor and detergent.