Abstract: A syringe (10) comprises a barrel (12), a plunger (14) and a retractable needle mount (16). The needle mount (16) is secured in an opening in one end (20) of the barrel by resiliently flexible arms (64) having shoulders (62) which cooperate with shoulders (32) defined in recesses (28) of the barrel wall (36) by insert ring (24) seated on step (22). The plunger piston (96) has slots (114) in an end face thereof which closely receive the distal portions (74) of the arms (64) widthwise. The slots (114) have surfaces (116) which act on the arms to disengage the arms from the recesses (28) and catches (122) which cooperate with catch surfaces (80) on the arms so that the needle mount (16) is withdrawn with the plunger (14). The barrel (12) includes integrally hinged guide members (126) to axially orientate the plunger (14) relative thereto and the plunger has catch means (140) which cooperates with the guide member (126) to secure the withdrawn plunger.