Abstract: A safety medical device having a sharpened needle is provided. After use, the needle is retracted so that the contaminated needle is shielded to prevent inadvertent contact with the contaminated needle. In one embodiment, the device includes a barrel and a plunger that is slidable within the barrel. The sharpened needle is operable between a projecting position and a retracted position. In the projecting position, the needle projects forwardly from the front end of the barrel. In the retracted position, the needle is shielded to prevent inadvertent contact with the needle. When the plunger is displaced forwardly to expel fluid from the barrel, the plunger actuates retraction so that the needle is automatically retracted after use. The needle may be included as an element of a needle assembly that is connectable with the barrel. The needle assembly includes a spring for biasing the needle toward the retracted position and a connector for attaching the needle to the barrel.