A hypodermic syringe barrel is provided with an external rotatable and slidable protective sleeve extendable and retractable relative to a needle mounted from the barrel and the sleeve is lightly biased toward the extended position thereof with the needle fully enclosed within the sleeve. The sleeve and barrel are operatively interconnected through utilization of a pin and slot connection defining limits of extension and retraction of the sleeve and the pin and slot connection includes structure whereby angular displacement of the sleeve relative to the barrel may be effected at each limit position of the sleeve for retaining the sleeve in that limit position.