A powder inhaler for administering powder by inhalation comprising: a flow path defined by a plurality of surfaces through which a stream of air is in use drawn on inhalation by a user; and dosing means (18) for providing a dose of powder to the flow path for entrainment in the stream of air; characterized in that the inhaler further comprises dislodging means for dislodging powder accumulated on a surface of the flow path downstream of the dosing means (18).