An assistance device for assisting in operation of an injection syringe including a syringe body carrying an injection needle covered with a protective cap. The assistance device includes a support for housing the syringe body, and a removal device for removing the protective cap, having a gripping member to be maneuvered by a user to remove this protective cap from the injection needle, and at least one extractor cooperating with the protective cap during removal of the protective cap. The removal device also has complementary members for controlling the extractor, which can be moved relative to each other in a relative engagement movement, to move the extractor between a reference configuration retracted relative to the protective cap and a cooperation configuration cooperating with the protective cap. The relative engagement movement is independent of the maneuvering movement applied by the user to the gripping member to remove the protective cap.
