An injection device is disclosed comprising a housing adapted to receive a syringe (114) which is moveable within the housing along a longitudinal axis (105) from a retracted position to an extended position in which the discharge nozzle of the syringe (114) extends from the housing. The device has an actuator and a drive (173) adapted to be acted upon by the actuator and in turn act upon the syringe (114) to advance it from its retracted position to its extended position to discharge its contents. A syringe carrier (127) is adapted to support the syringe (114) as it is advanced and there is a locking mechanism (170) between the syringe carrier (127) and the drive (173) to inhibit movement of the syringe carrier (127) and syringe (114) towards the exit aperture when not acted upon by the drive (173).
