A safety syringe assembly (10) adapted for use in an autoinjector comprising a syringe (12) and a first sleeve (22) that at least partially surrounds the syringe. The syringe has a barrel (14) for holding a volume of medicament, a needle (18) at one end of the barrel, and a plunger (20), axially moveable within the barrel. The syringe is axially moveable relative to the first sleeve between a first position, in which the needle is exposed, and a second position, in which the needle is surrounded by the first sleeve and is not exposed. The syringe is axially lockable with respect to the first sleeve when in the second position.
