Abstract: The present invention relates to a concrete mixer comprising a drum (1) sustained by a supporting structure (3) allowing the drum tilting, said drum (1) being connected with a motorgear unit (2) driving the rotation thereof around a respective longitudinal axis (z-z), wherein said drum (1) is provided with an annular track (14) exhibiting an external or circumferential edge (140) engaged by respective driving means comprising more rollers (20) which are apt to rotate about respective axis?, are connected with said motorgear (2) and interact with said edge (140) in points (CP) located on segments (S) joining the points of intersection of the axis? of the rollers (20) and of the drum (1) with a plane traversing the track (14). (FIG. 14).