A dispersing unit for a powder inhaler comprises a mouthpiece (10) with an annularchannel (12) for the delivery of a stream of particles. The annular channel hasan axial inlet (14), and an axial outlet (16) adjoined by an annular deflectionchamber (18) in which the axially incoming stream of particles is deflected toa predominantly radial direction of flow. The deflection chamber is adjoinedin the axial direction by a rotation chamber (20) with a circular peripheral wall(22) and an axial outlet (24).
