An injection device 110 is described having a housing 112 that receives a syringe 114 having a needle 118, wherein the syringe is supported in a syringe carrier 150. The syringe 114 and syringe carrier 150 are biased by a return spring 126 from an extended position in which the needle 118 extends from the housing 112 through an exit aperture 128 to a retracted position in which it does not. A drive spring 130 acts via a drive to advance the syringe 114 from its retracted position to its extended position and discharge its contents through the needle 118 and a return spring 126, brought into play when the drive has reached a nominal return position, restores the syringe 114 to its retracted position. The injection device is less prone to failure than prior art devices and is safer should failure occur.