Abstract: A passively activated safety needle assembly includes a needle assembly, a shield assembly and a safety cap. The needle assembly includes a hub and a needle cannula that projects from the hub. The shield assembly includes a safety shield that is mounting for sliding movement along the needle cannula. The shield assembly also includes a plurality of arms articulated to one another to permit sliding movement of the safety shield along the needle cannula from a proximal position to a distal position where the tip of the needle cannula is shielded. A spring is mounted to the shield assembly and is operative to drive the safety shield from its proximal position to its distal position. The safety cap is mounted over shield assembly and holds the shield assembly in the proximal position. The arms are held during usage of the safety needle. Upon release of the arms, the spring automatically drives the shield distally without any user activation.