The invention relates to a device for back-injecting an implant (30) into a subject skin (22) comprising a main hollow body (10) provided with a hollow needle (28) which is fixed thereto and in which the implant (30) is introduced, a secondary body (12, 114) which is coaxially arranged in the main body (10) and surrounds the needle (28) and a piston rod (88) which coaxially slides inside the hollow needle (28) and whose position with respect to said needle (28) remains unchanged when the back-injection device (1) is pressed against the subject skin (22) in such a way that the needle (28) is enabled to penetrate therein and the secondary body (12) is retracted inside the maim body (10), wherein the piston (8) penetrates inside the hollow needle (28) for maintaining the implant (30) at a required depth in the subject skin (22) during the withdrawal of the hollow needle (28) from the subject skin (22) when the secondary body (12, 114) exits from the main body (10). The inventive device is characterised in that it comprises elastic means for returning the secondary body (12) from the main body (10).Linvention concerne un dispositif pour la rétro-injection dun implant (30) dans la peau (22) dun sujet, ce dispositif (1) comprenant un corps principal creux (10) auquel est fixée une aiguille creuse (28) dans laquelle est introduit limplant (30), un corps secondaire (12 114) disposé coaxialement à lintérieur du corps principal (10) et entourant laiguille (28), et une tige de piston (88) susceptible de coulisser coaxialement à lintérieur de ladite aiguille creuse (28) et dont la position relativement à cette aiguille (28) reste inchangée lorsque le dispositif de rétro-injection (1) est pressé contre la peau (22) du sujet pour permettre à laiguille (28) de pénétrer dans la peau (22) dudit sujet et que le corps secondaire (12) se rétracte à lintérieur du corps principal (10), la tige de piston (8) senfonçant à lintérieur de laiguille creuse (28) pour maintenir limplant (30) à l
