Any investigation of environmental processes related to chemical substances or their effects depends on reliable, comparable analytical data. This also holds true for the impact of climate change on occurrence, distribution and effects of emerging pollutants, with respect to which there is particular concern regarding the reliability of analytical data, due to lack of harmonization in method validation and requirements for quality assurance and quality control (QA/QC). We present a recent European approach to developing a harmonized framework for method validation, QA/QC and provision of environmental data on emerging pollutants. The validation approach has been tested and improved by three case studies. We outline the main concept of the validation approach as well as the results of the case studies. This European validation framework turned out to be a feasible tool to check the fitness for purpose of analytical methods and to improve the reliability of environmental analytical data, particularly for emerging pollutants.