A needle stick protection device includes a distal shield member having a slot which allows a needle to freely pass between shielded and unshielded positions an infinite number of times. The needle stick protection device also includes a proximal base member and a hinge connecting the distal shield member to the proximal base member. A locking mechanism secures the proximal base member to the distal shield member. The locking mechanism includes a compressive sleeve of the distal shield member and a distal cylindrical collar of the proximal base member, which frictionally fit together in a manner securing the proximal base member and the distal shield member.