An automatic core-charging and bobbin-discharging group in a plastic film winding machine, positioned partially juxtaposed and partially below a winding reel includes a core charging portion having a motorized linear actuator carrying a guide-support which houses a certain number of cores suitable for receiving plastic film, the guide-support being movable, backwards and forwards, between a position associated with a core charger and a juxtaposed position, axially parallel to a spindle of the winding reel, with the cores inserted on the spindle, the linear actuator also being vertically liftable with a variation in an external diameter of the cores, and a bobbin discharging portion having a motorized conveyor belt, equipped with an extendable portion, movable between a position below a spindle carrying the wound bobbins and a discharging portion of the bobbins, the conveyor belt being vertically liftable with a variation in an external diameter of the bobbins.