There is provided a medicament delivery device comprising a housing for receiving a syringe, the housing having first and second casing parts separably attachable to one another. The device further comprising a sleeve receivable within the housing and including a tubular wall having an inner surface delimiting a bore and an opposing outer surface. A locking member is receivable within the second casing part such that the locking member is axially movable between first and second axial positions relative to the second casing part. In the first axial position the locking member is engageable with the outer surface to inhibit an axial movement of the sleeve relative to the first casing part. In the second axial position the locking member is disengageable from the outer surface. The device may have application as an autoinjector.
