The research area of polymer/clay nanocomposites has attracted a great deal of attention over the last two decades. Outstanding improvements in physical properties of polymeric matrices (e.g. stiffness, strength, heat distortion temperature, reduced permeability to gas and liquids, fire retardancy), can be expected with only few weight percents of nanofiller, therefore promising to eliminate the typical compromise between properties and processability of composite materials. While most of the literature focuses on the use of smectite (layered) clays, less work has been carried out on other clays. We have extensively studied the use of sepiolite nanoclay as potential nanofiller for a whole range of polymers incl. unsaturated polyester, epoxy, PP, PA, and PLA. Sepiolite is a hydrated magnesium silicate which is characterised by a needle-like shape. These fibrous fillers are generally more easily dispersible than layered nanoclays as the specific surface area of needle-like fillers is lower than platelet-like fillers of the same aspect ratio. Sepiolite clays have already shown interesting mechanical reinforcing capability but also improved rheological properties, thermal stability and fire retardancy (especially in combination with carbon nanotubes). Moreover, the fibrous shape of sepiolite offers unique potential as nanofiller in oriented (1D) polymer systems such as fibres, tapes or films.