The invention is directed to a brush section for an electric toothbrush with a handle section comprising an electric motor, wherein the brush section is adapted to be connected with the handle section and has at its end remote from the handle section an essentially circular cylindrical rotary bristle supporting structure (38) on which bristles (48, 50) are arranged in the form of tufts (60, 62) of different lengths, and wherein the bristle supporting structure (38) has its axis of rotation at approximately right angles to a longitudinal center line of the brush section and is adapted to be driven in an alternating rotary motion over an arc of .+-.20.degree. to .+-.100.degree.. Some of the tufts (60) of bristles are serially located in position on a diameter and on an outer circular ring of the bristle supporting structure (38).