A needlestick prevention device (100) for an injection needle carried by a needle-bearing member (101) of a syringe (102) is formed as a one-piece moulding and comprises a first part (103) adapted to be attached to the needle-bearing member (101) and a second part (104) providing a shield for the needle and pivotally movable relative to the first part to expose the needle for use. The device is adapted to adopt a first position in which the needle is protected for transport of the device prior to use, a second position in which the needle is exposed for filling of the syringe and injection, a third position in which the needle is protected after filling of the syringe but before injection and a fourth position in which the needle is locked in the device following injection. In one embodiment the shield (104) has a transport recess (124) and a locking recess (125) connected by a gate device (126), the arrangement being such that in the third position the needle (130) is in the transport recess (124) and is able to move into the second position, and in the fourth position the needle moves through the gate device (126) into the locking recess (125), with the gate device (126) preventing movement out of the fourth position. The device also includes energy-dissipating bumps (155) operative to reduce the energy of the shield (104) as it is returned to the third position and before the gate device contacts the needle (130) in order to prevent splattering of any liquid on the needle (130) out of the device.La présente invention concerne un dispositif de prévention contre les piqûres d'aiguille (100) pour une aiguille d'injection portée par un élément porte-aiguille (101) d'une seringue (102), ledit dispositif se présentant sous la forme d'un moulage monobloc et comprenant une première partie (103) conçue pour être fixée à l'élément porte-aiguille (101) et une seconde partie (104) fournissant un élément de protection de l'aiguille et mobile de manière pivotante par rapport à
