Polypropylene (PP) fibres have an extensive range of applications, including filtration, composites, biomaterials and electronics. In these applications, the surface properties of the fibres are particularly important. This paper presents examples of the use of gas plasma technology to create functional nanostructures on PP fibre surfaces, which render the surfaces hydrophilic. It is also shown how these treatments can be regulated to produce the desired level of hydrophilicity for a given application. Three principal modifications have been performed, to create functional nanostructures: plasma activation with oxygen gas plasma, grafting of polyacrylic acid following argon gas plasma treatment, and plasma-enhanced deposition of silver. Atomic force microscopy (AFM) and environmental scanning electron microscopy (ESEM) were employed to characterise the morphology, surface structure and composition of the fibres treated by gas plasma. © 2005 Springer Science + Business Media, Inc.