The invention relates to a tool (1) for removing a cap (3) from a medical injection device comprising a body and a needle extending distally from the body, the cap covering the needle, said tool being characterized in that it comprises a pair of opposite jaws (10, 11) connected by an elastic interface (12), each jaw comprising:- a distal portion (10b, 11b) forming a distal clamp configured to surround at least a part of the cap；- a proximal portion (10a, 11a) forming a proximal clamp configured to be removably axially fixed to a body of the medical injection device；the elastic interface forming a fulcrum (12) located between the distal and proximal portions such that a pinching force exerted radially inwardly onto the distal portion (10b, 11b) of the jaws causes the proximal portion (10a, 11a) of the jaws to expand radially outwardly；the tool being operable between:- a rest position wherein the proximal portion (10a, 11a) of the jaws rigidly engages the body of the medical injection device, the distal portion (10b, 11b) of the jaws being distant from the cap, and- an operative position wherein the distal portion (10b, 11b) of the jaws is pinched so that said distal portion (10b, 11b) engages the cap and the proximal portion (10a, 11a) disengages from the body of the medical injection device.
