An injection apparatus, e.g. auto-injector, comprises a housing 4 and an injector sub-assembly 6 located within the housing. The injector sub-assembly includes a needle 20, a syringe barrel 18 and a piston. The injector sub-assembly is slidably mounted within the housing between an operative configuration (Fig. 2) in which the needle projects from the housing, and a retracted configuration in which the needle is within the housing. A needle exit door 44 is pivotally connected to the body such that the door closes a needle exit aperture to cover the needle when the injector sub-assembly is retracted and opens when the injector sub-assembly is in its operative configuration. When closed the door minimises contamination of the needle allowing it to be re-used. The door is preferably coupled to the injector sub-assembly so that the door moves from a closed position to an open position as the sub-assembly moves from a retracted to an operative position. Motors 8, 24 may be provided for moving the sub-assembly and providing a dose of medicament respectively.
