Abstract: The present invention relates to a mixer for concrete and similar mixtures, of the type composed of a parallelepiped tank (2) internally provided with one or more mixing shafts (3), each of them driven into rotation by a corresponding motor unit (UM) in external position with respect to the tank (2), which comprises, with the necessary connections, an electric motor (4), a gear motor (6) and an intermediate gear (7) interfaced with the end of the corresponding mixing shaft (3), characterised by the fact that the electrical motor (4) and the corresponding gear motor (6) of each motor unit (UM) are fixed to a single bearing frame (8) that is hung to the border of the tank (2) by means of one or more hinges (9).