Abstract: A medicament delivery device has a reservoir within a housing and means for driving medicament from the reservoir. The device is provided with a filling mechanism upon which a medicament container sealed by a penetrable stopper is mounted. The mechanism comprises an internal bore which accommodates an internal rod from which a needle projects. Needle is hollow and is in communication with the reservoir. In order to fill the reservoir, the container is pressed into the bore, causing the needle to pierce the stopper, the stopper abutting against the rod and acting as a piston to drive medicament from the container as the container is pushed into the bore and moves relative to the stopper. Thus, the reservoir can be filled with the sterile medicament which is stable when stored in the container, and the filling is easily accomplished without the use of a syringe. A further advantageous feature is provided by a delivery needle which is mounted on the periphery of the lower surface of the housing.