This report gives an overview on the subject of regulating nanotechnology. Such regulating nanotechnology touches a number of issues. Normative aspects of designing regulation under uncertainty and technology assessment are equally important as an evaluation of the potential effects and the existing regulations as such. This report is concerned with a detailed step-by-step introduction to all relevant issues. Firstly, it introduces the Precautionary Principle as a concept to take action under the uncertainty in policy-making. Secondly, traces first hints regarding possible adverse effects by assessing nanotechnology with the approach of "characterisation of technology". Thirdly, the report presents the latest research results on the possible hazardous effects of nanotechnology applications. Finally, areas of regulatory concern with the focus on chemicals and cosmetics are discussed with regard to nanotechnology. The last part presents a number of recommendations for future policy design.