A head for hedge trimmer includes an external casing intended to rotate around an axis of rotation and equipped with at least one lateral exit hole for a cutting wire, the external casing internally presents a seating for the storage of a part of the cutting wire so that an end portion of the wire exits from the casing through a lateral hole. The head further includes, within the seating, a pair of presser discs facing each other and defining between them an annular shaped housing to contain part of the cutting wire. The presser elements are movable towards each other along the axis of rotation for compressing between them the part of the cutting wire stored between them.