An autoinjector comprising an outer housing in which can be mounted a syringe for holding a volume of medicament, the syringe for holding medicament having a needle at one end thereof, a syringe holder for supporting the syringe in an axial position relative to the outer housing, and an intermediate housing at least part of which is located within said outer housing, characterised in that said intermediate housing is provided with a blocking means capable of abutting the syringe or the syringe holder so as to be capable of preventing forward axial movement of the syringe when a forward axial force is applied to said needle before actuation of the autoinjector to deliver an injection, but incapable of preventing forward axial movement of the syringe during actuation of the autoinjector to deliver an injection.