We propose a methodology to monitor the quality of the meta-data used to describe content in web portals. It is based on the analysis of the meta-data using statistics, visualization and data mining tools. The methodology enables the site’s editor to detect and correct problems in the description of contents, thus improving the quality of the web portal and the satisfaction of its users. We also define a general architecture for a platform to support the proposed methodology. We have implemented this platform and tested it on a Portuguese portal for management executives. The results validate the methodology proposed.