A portable device (2) for harvesting small fruits from a plant, by causing a vibration or a shaking movement, comprises an elongated support that is configured to be grasped (20) and has an enlarged end portion (21 ); two comb-like elements (30', 30") hinged in a first point of the enlarged end portion, each having an array (35) of fingers (36) that extends from an elongated base member (31 ',31 ") opposite to the support; an actuation unit (50) mounted to the support; a transmission mechanism (40) between the actuation unit and the comb-like elements having a transmission stem (41 ) slidably arranged along the support and connected at an own end portion (42) to the actuation unit, with two links (48) each hinged (33) in a different point of a comb-like element, and with a pin (45), at the opposite end portion (43), which is located on the transmission axis (44). The transmission mechanism is arranged to cause the stem (41 ) to reciprocate along the support, so that its end portion (43) bearing the pin (45),