Abstract: A safety needle (20) for use with a syringe including a casing (30) in which a needle (28) for injections or blood drawing is mounted. A sleeve (22) is slidably mounted in the casing (30). The sleeve (22) is biased by a spring (42) into a partially extended position, exposing only the sharp tip (26) of the needle. As the needle (28) is inserted into a patient, the sleeve (22) retracts into the casing. When the needle (28) is removed, the sleeve (22) returns to a fully extended position and by operation of a locking mechanism locks into place. The locking mechanism includes a plurality of fingers (62), at least one of which has a projection (64) formed thereon. The projection (64) travels along a track system (66) integrally formed in the inner wall (56) of the casing (30) to move from the initial sleeve position to the retracted position and then back to a locked position in which contact with the used needle (28) and reuse of the safety needle (20) is prevented.