Abstract: A disposable mixing syringe especially adapted for dental use is described. It comprises a barrel of uniform inside diameter divided by a fixed diaphragm into upper and lower chambers for receiving respectively first and second components of a mixture to be formed and terminating in a nozzle having a small orifice. A removable closure seals the opposite barrel end. Inserting a mixing tool through the diaphragm allows rapid mixing of the constituents, after which a suitable plunger is provided to expel the contents through the orifice.