In an assembly for actuating a syringe, two gripping devices are designed to receive and withhold a containment cylinder and, respectively, a piston of the syringe, and are defined by respective pairs of jaws for gripping a flange of the containment cylinder and, respectively, of an end head of the piston, the jaws of at least one gripping device being mobile with respect to one another between a gripping position and a release position under the thrust of a corresponding actuation device.