Abstract: The invention relates to a method and to a device for producing synthetic grass fibers for artificial turf. For said purpose, a plurality of strips formed from a divided film or a plurality of individually extruded monofilaments made of a polymer material are produced in an extrusion process. The strips or monofilaments are then stretched and wound individually or as a fiber bundle to form coils. According to the invention, in order to in particular influence the physical properties of the synthetic grass fibers in addition to the visual properties, the roughness of the surfaces of the strips or monofilaments is changed before or after the winding. For said purpose, the device according to the invention has a treatment apparatus, the means of which are suitable for changing the surface roughness of the strips or monofilaments.