The present invention provides a hair dryer air diffuser elastically fitted to the nozzle of a hand held hair dryer. The air diffuser is substantially conical in shape and is made of flexible material. The air diffuser has openings or slits in the flexible material. Preferably, hair treatment products are affixed to or embedded in the flexible material. As the hair is dried, the heat in the air emerging from the dryer, volatilizes the hair treatment products and deposits them on the hair.