A diffuser includes an air inlet for receiving an airflow from a hair dryer, a grille having a plurality of air outlets for emitting a first part of the airflow from the diffuser, and a plurality of projections upstanding from the grille for contacting the hair of a user and for emitting a second part of the airflow. Each of the projections has a respective air outlet located in an end portion of the projection which is remote from the grille. The projections are divided into a first set of projections and a second set of projections arranged about the first set of projections. The air outlets of the first set of projections are arranged to emit air towards the second set of projections, and the air outlets of the second set of projections face are arranged to emit air towards the first set of projections.