When the dimensions of materials reduce in one or more dimensions, their physical and chemical properties significantly vary due to the increasing surface-to-volume ratio. Today, the textile industry uses nanoparticles and nanostructured materials, nanocomposites and nanofibres, which are primarily used as functional textiles with specific characteristics. In this paper, we present nanomaterials with an antistatic, antimicrobial, self-cleaning and reinforcement function. Moreover, some nanomaterials for the development of hydrophobic, UV-resistant and fire-resistant fabrics are presented. A specific topic includes smart textiles with embedded nanosensors, and fabrics with a controlled release of active ingredients, drugs or fragrances. Furthermore, a separate chapter deals with the effects and risks of nanotechnologies/nanomaterials for the environment and health.