Device (100) for injection of fluid product having a syringe body (101) and a needle (110) fixed in an axial end projection (102) of the syringe body said injection device having a needle protection device (200) said protection device being fixed on said injection device in a storage position said protection device being removable from said injection device said protection device having an internal body (210) made of substantially flexible or deformable material and an external body (220) made of substantially rigid material said internal body (210) in the storage position closing the dispensing orifice (111) of said needle (110) in a leaktight manner and cooperating with said injection device (100) in a leaktight manner and said external body (220) cooperating with said injection device (100) in the storage position in order to fix said protection device (200) on said injection device (100) said internal body (210) having a radial projection (215) and said external body (220) has a radial shoulder (225) and a radial end edge (226) defining an upper axial opening said internal body (210) being inserted into said external body (220) through said upper axial opening with said radial projection (215) in abutment on said radial shoulder (225) said axial end edge (226) of said external body (220) being folded back on said internal body (210) in order to fix said internal body (210) in said external body (220).
