Method for making plastic fiber for application in concrete with largest grain diameters >4 mm, with an average diameter of 0.15 to 2 mm, corresponding to approximately 160 to 28,000 dtex. Using a co-extrusion process, a bi-component fiber is formed having a central core and a casing around the central core, the central core and the casing contain different pure polymers or polymer mixtures, and then the co-extruded bi-component fiber is stretched by a factor of 5 to 15, and thereafter a structured or grooved surface is embossed onto the co-extruded stretched bi-component fiber. The embossing is performed such that a depth of the embossing is more than 10% of an average fiber diameter, and a maximal distances of structure tips within incorporated structures of the embossing in an axial direction lie in a region between 0.5 mm and 3 mm.