A multi-dose injector comprising an inner housing (16) and an outer housing (12), the inner housing (16) being movable within the outer housing for a defined distance, a plunger rod (20) comprising a shaft (66) mounted within the inner housing, (16) the (66) shaft having a plurality of spaced apart teeth (68) formed thereon, an actuator (22) located at one end of the shaft (66), the inner housing (16) having at least one pawl (70) arranged to engage with the teeth (68), a syringe (74) mounted interiorly of the inner housing (16), the syringe being arranged such that the shaft engages with a plunger (76) within the syringe, and a spring member (18), the spring member (18) being biased between the inner housing (16) and the outer housing (12).