The organization may communicate its engagement in sustainability and may presents results achieved in this field by creating and publishing corporate social responsibility (CSR) reports. Today, we can observe a growing number of companies issuing such reports as a part of their annual reports or as stand-alone CSR reports.Despite the increase in the number of such reports their quality is different. CSR reports do not always provide complete data that readers desire, which in turn intensifies the problem with the evaluation and comparison of the organization’s results achieved in this scope. Differences also occur between reporting models used in different EU countries caused by, inter alia, differently applied EU legislation on the disclosure of non-financial information in different Member States. This paper is one of the first attempts to perform a quantitative and qualitative analysis of corporate sustainability reporting practices in several European Union countries. The purpose of this article is to present the current state of CSR reporting practices in selected EU Member States and identify the differences in the quality and level of this kind of practices, taking into account the mandatory and voluntary model of disclosure. The study included separate CSR reports as well as annual reports with CSR sections and integrated reports published in 2012 in six selected EU Member States. The authors have used a specific evaluation tool in the examination of the individual reports. The assessment questionnaire consists of seventeen criteria grouped into two categories (relevance and credibility of information). In order to assess the quality of examined reports, the authors aggregated the indicators related with the reporting practices. The findings show that the quality level of the studied reports is generally low. Referring to its components, the relevance of the information provided in the assessed reports is at the higher level than its credibility. The study also indicates that the legal obligation of CSR data disclosure has a positive effect on the quality of CSR reports.