Purpose – The purpose of this comparative analysis is to assess the range of functions offered by five citation managers: Citace PRO, Citavi, EndNote, Mendeley and Zotero. Design/Methodology/Approach – Based on established criteria and expert resources the analyzed functions were defined. Particular functions were tested using real-time data on publications or by using full texts directly. Results – The results describe the strengths and weaknesses of the specific citation managers within the eight functional clusters. There are presented functions included in all tools as well as specific ones (e.g. advanced information management in Citavi), or specific approach to their setting (e.g. formats for export of references in individual tools). Finally, the authors offer functional range comparison among the tested tools in order to compare their range in the whole and in individual clusters to summarize the specializations of tools in a certain area (e.g. collaborative and communication functions in Mendeley). Originality/Value – The scope of functions is the basic criterion for the selection of the suitable tool for a specific user as well as a starting point for educating users to use citation managers effectively. The aim of the article is not to compare the user's view of the tools and the functions offered but a description of these functions and their scope.