The safety support device for a syringe comprises a support sheath (16)
for the body (10) of the syringe and an inner sheath (18) suitable for
sliding relative to the support sheath between a waiting, retracted
position and an extended position for protecting the needle (14) of the
syringe. The device has means for holding the syringe body (10) relative
to the support sheath (16) and retaining means (30, 32, 22) suitable for
being activated to retain the inner sheath in the waiting, retracted
position inside the support sheath and for being deactivated by the
piston (12) of the syringe to allow the inner sheath (18) to extend into
its protective, extended position.