A safety needle device is disclosed having a housing configured to couple to a syringe, the housing having a proximal end, a distal end, and a housing body. A first guide path, a second guide path and a third guide path may be disposed on the housing body. A needle hub is disposed on the proximal end of the housing and a needle cannula is attached to the needle hub. The device having a retractable sheath configured to move between an initial position, a retracted position and an extended position with respect to the housing, wherein the initial position partially exposes a distal tip of the needle cannula, the retracted position fully exposes the needle cannula, and the extended position fully covers the distal tip of the needle cannula. The retractable sheath also may have a guide element. The first, second and third guide paths are configured to slidingly receive the guide element. The device also having a first locking member, a second locking member, a rotating cam disposed in the housing body, and a spring element to bias the retractable sheath to an extended state to cover the distal end of the needle cannula upon completion of an injection.