An autoinjection device has front and rear separable assemblies (10) and (12). The rear assembly contains a drive assembly which is triggered or unlatched by rearward movement of an actuating sleeve (14) extending from the front assembly. A locking dial (16) is provided which locks the actuating sleeve against rearward movement until the dial is moved to an unlocked position. The dial automatically returns to a locked position upon initial rearward movement of the actuating member (14), so that, when the actuating member (14) moves forwardly after completion of an injection, it locks out to shroud the needle of the autoinjection device. The docking dial can be made integral with the actuating member (14) in an alternative embodiment.
