A medicament delivery device comprising: a syringe having a needle; a housing adapted for receiving the syringe such that the syringe is axially moveable relative to the housing between a first axial syringe position and a second axial syringe position, the second axial syringe position being axially forward of the first axial syringe position; a needle shield axially moveable relative to the housing, the needle shield being moveable between a first axial shield position and a second axial shield position, the second axial shield position being axially forward of the first axial shield position, for selectively covering the needle of the received syringe; a biasing member for biasing said needle shield axially forwardly from the first axial shield position to the second axial shield position; and at least one blocking member which is radially moveable from a first radial position to a second radial position in response to a forward axial movement of the syringe; wherein in a first configuration the syringe is in the first axial syringe position, the needle shield is in the first axial shield position and the blocking member is in the first radial position, such that the needle is covered by the needle shield and the blocking member prevents the biasing member from biasing the needle shield to the second axial shield position; in a second configuration the syringe is in the second axial syringe position, the needle shield is in the first axial shield position, or a position axially rearward of the first axial shield position, and the blocking member is in the second radial position, by virtue of forward axial movement of the syringe, such that the blocking member permits the biasing member to bias the needle shield to the second axial shield position; and in a third configuration the syringe is in the second axial syringe position, or a position axially forward of the second axial syringe position, and the needle shield is in the second axial shield position, such that the needle is covered by the needle shield; wherein the second configuration is subsequent to the first configuration and the third configuration is subsequent to the second configuration whereby the needle shield comprises the at least one blocking member. a syringe having a needle; a housing adapted for receiving the syringe such that the syringe is axially moveable relative to the housing between a first axial syringe position and a second axial syringe position, the second axial syringe position being axially forward of the first axial syringe position; a needle shield axially moveable relative to the housing, the needle shield being moveable between a first axial shield position and a second axial shield position, the second axial shield position being axially forward of the first axial shield position, for selectively covering the needle of the received syringe; a biasing member for biasing said needle shield axially forwardly from the first axial shield position to the second axial shield position; and at least one blocking member which is radially moveable from a first radial position to a second radial position in response to a forward axial movement of the syringe; wherein in a first configuration the syringe is in the first axial syringe position, the needle shield is in the first axial shield position and the blocking member is in the first radial position, such that the needle is covered by the needle shield and the blocking member prevents the biasing member from biasing the needle shield to the second axial shield position; in a second configuration the syringe is in the second axial syringe position, the needle shield is in the first axial shield position, or a position axially rearward of the first axial shield position, and the blocking member is in the second radial position, by virtue of forward axial movement of the syringe, such that the blocking member permits the biasing member to bias the needle shield to the second axial shield position; and in a third configuration the syringe is in the second axial syringe position, or a position axially forward of the second axial syringe position, and the needle shield is in the second axial shield position, such that the needle is covered by the needle shield; wherein the second configuration is subsequent to the first configuration and the third configuration is subsequent to the second configuration whereby the needle shield comprises the at least one blocking member.