A portable beating device (1) for picking fruit off trees, in particular for picking olives, and which has: a supporting body (11) a slide (12) slidable along a translation axis (S) with respect to the supporting body (11) a transmission system (13) for translating the slide (12) back and forth along the translation axis (S) and two beating members (3) each beating member having an arm (30), which extends along a longitudinal axis (B) from the supporting body (11) and is hinged to the slide (12) by a hinge pin (23), and a plurality of side by side prongs (31), which project from the arm (30) and the arms (30) being connected to the supporting body (11) by respective joints (37), which allow the arms (30) to slide along their respective longitudinal axes (B), inside the respective joints (37), as the arms (30) rotate about the hinge pins (23).
