Abstract: A single-lever mixing valve has a housing, a cartridge fixed in the housing and having an actuating element pivotal about an element axis for adjusting flow through the cartridge, and an actuating shaft centered on the element axis, fixed in the actuating element, and having a first end formed with an axially open threaded bore and an opposite second end formed with an axially oppositely open grooved seat. The ends of the shaft are generally flush with an outer surface of the cartridge. An actuating lever has first and second connecting pins extending along the element axis and juxtaposed with the respective ends of the shaft. A screw projecting through the first pin and threaded into the bore of the first shaft end fixes the first pin to the first shaft end relative to the element axis. An adapter has an inner end nonrotatably fitted but axially displaceable in the grooved seat of the second shaft end and an outer end juxtaposed with the second pin of the actuating lever.