Abstract. Automatic benchmarking can provide a reliable first insight into the accessibility status of a web site. The eGovMon project has developed a tool which can assess web sites according to a statistically sound sampling procedure. Additionally, the tool supports detailed evaluation of single web pages. This paper describes the process of data acquisition for the case of large scale accessibility benchmarking of Norwegian public web sites. An important contribution is the elaborated approach to communicate the results to the public web site owners which can help them to improve the quality of their web sites. An on-line interface enables them to perform evaluations of single web pages and receive immediate feedback. The close collaboration with the municipalities has lead to an overall higher quality both of Norwegian public web sites, the eGovMon tool and the underlying methodology. Automated evaluation alone can not capture the whole picture, and should rather be seen as a complement to manual web accessibility evaluations. The Norwegian Agency for Public Management and eGovernment (DIFI / Norge.no) carries out an annual web quality survey that includes manual assessment of web accessibility. We present a comparison between the Norge.no results and the data collected by the eGovMon tool and verify the statistical correlation.