A protection device with improved functionality, particularly for syringes, comprising a supporting body which is provided with a through hole for the insertion of the covering cap of a needle of a syringe, the supporting body being provided with at least one flat face, being arranged on the opposite side with respect to a face for the insertion of the covering cap in the hole, for the resting contact of the supporting body on a resting surface, the face lying opposite the flat face being provided with a raised perimetric containment rim, the hole having a diameter that is substantially larger than the diameter of the central portion of the covering cap and substantially smaller than the diameter of the end portion of the covering cap, a collar being provided around the hole, the collar extending from the face for the insertion of the covering cap.