An endoscopic injection needle device includes a flexible elongate sheath attached to a handle. Disposed within the sheath is drive shaft having a lumen within and a needle at its distal end. The drive shaft is movable longitudinally within the sheath and is attached at its proximal end within the handle to an actuator. Advancing the actuator extends the needle from the distal end of the device. The actuator includes a locking mechanism that locks it in place with the handle when advanced a certain distance. The locking mechanism includes multiple locking positions wherein the exposed length of the needle corresponds to the distance advanced by the actuator at each locking position. Also included in the distal end of the sheath are a spring coil and a collar. The collar is positioned distal to the spring coil and includes a dome shaped distal end that extends beyond the distal end of the sheath. The drive shaft extends through the spring coil and, when retracted, the needle is housed within the collar. The spring coil and collar stabilize the distal end of the sheath, facilitating consistent deployment and retraction of the needle.