A controlled or zero backlash gearmotor comprises a main gearmotor, a secondary service gearmotor, an electronic control unit and transmission and synchronization gears. The backslash control results from the cooperation between the main gearmotor, the secondary service gearmotor, and the electronic control unit which adjusts, based on parameters detected by a series of sensors, the load provided by the service gearmotor on one of two irreversible screws pressing on two worm screws, respectively, arranged at the side of a worm wheel. This latter supports a secondary shaft and is get into gear with both the worm screws, the two worm screws being synchronized by means of gears connecting them to each other so that a reversible motion transmission is executable.