Nanotechnology is developing into one of the most challenging issues in food and feed safety.  The public is highly sensitised and a lack of information about this new technology caters for increasing scepticism throughout the societies.  Politicians took up the issue and many actions are at stake.  The main points to tackle are the definition of the term “nano”, the transparence about nanotechnology already applied in practice, the risk assessment for different nanotechnology applications, and the way to evaluate new nanotechnology applications.  Against this background, the presentation reflects on regulatory aspects of evaluating nanomaterials in animal feed in the E.U. and U.S.   Further, this presentation identifies some of the most important information gaps that science should tackle in the near future .