Abstract: The present invention relates to a syringe for delivering only a single dose of a medicament at each actuation of the syringe. The device includes a cylinder which is adapted to contain the medicament, the cylinder having a piston which is journalled in the bore of the cylinder for axial movement in the bore towards an outlet. The piston can be moved axially within the bore of the cylinder by means of a plunger member which carries one or more drive teeth which are adapted to engage teeth carried by an axially moveable drive member. The axial spacing between the axially adjacent teeth on either the plunger member or the drive member corresponds to the forward axial movement of the plunger member which is required to discharge a single dose of medicament. The drive member can also be retracted axially only a predetermined distance which corresponds to one of the tooth spacings with respect to the plunger.