An injection device having an outer housing configured to receive a syringe.The syringe has a barrel for containingmedicament and a needle in fluid communication with the barrel. The devicefurther has a needle shield axially moveable relative tothe outer housing between a needle covering position and a needle exposingposition and a biasing means to bias the needle shieldaxially forwardly toward the needle covering position. A locking sleeve,axially movable relative to the outer housing between anon- locking position and a locking position, selectively limits axialmovement of the needle shield. In a first configuration, theneedle shield is axially slideable within the locking sleeve to permitrearward axial movement of the needle shield from the needlecovering position to the needle exposing position. In a subsequentconfiguration, the needle shield is prevented from moving axiallyrearwardly by interference with the locking sleeve, thereby maintaining theneedle shield in the needle protecting position. Thedevice may reduce the risk of needle stick injuries when compared to knowninjection devices and also may prevent unintentional reuseof the device.
