A fluid injection device having a syringe body, a needle, and a needle protection device removable from the injection device and having a substantially flexible or deformable inner body and a substantially rigid outer body. In the stored position the inner body closes the dispenser orifice of the needle and the outer body co-operates with the injection device to fasten the protection device on the injection device. The protection device includes a protection system against accidental pricking, having protective flaps that are integral part of the outer body and movable between a covering position in which they cover the needle, and an open position in which the needle is uncovered. The protection system has a control ring that slides over the outer body so as to move the flaps from their covering position to their open position, before injection, and from their open position to their covering position, after injection.
