Abstract: A machine for automatically marking electric wires, leads and the like, by means of small rings made of plastic material, provided with symbols, and joined together by weakened breaking portions, to form a sort of flexible tube.According to the invention, the machine comprises a marking tube magazine supported rotating on an axis, and a feeding device for moving, by one ring at a time, any one of said marking tubes towards a delivering point in which each individual ring is broken off. The machine comprises moreover a ring-gripping and tearing member, capable of automatically tearing and positioning each ring in front of a hollow needle movable from a backward position to a forward position with respect to the gripping member; and furthermore comprises a device for transferring each ring or combination of rings from the needle onto a wire, inserted into the same hollow needle.